diff --git a/.travis.yml b/.travis.yml
index b3d1677d..775235c3 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -28,293 +28,22 @@ env:
 matrix:
   include:
 
-  # Valgrind
-
   - os: linux
     compiler: gcc
-    env:
-      - COMPILER=g++-4.9
-      - SPECIAL=valgrind
+    env: COMPILER=clang-3.8
     addons:
       apt:
-        sources: ['ubuntu-toolchain-r-test']
-        packages: [g++-4.9, valgrind]
-    after_success:
-      - make check TEST_PREFIX="valgrind --error-exitcode=1 --leak-check=full " TEST_PATTERN=""
-
-  # cLang sanitizer
-  # note: sadly clang's libc++ has errors when running with sanitize,
-  # so we use clang with gcc's libstdc++ which doesn't give those error.
-  # that's why we need to install g++-6 to get the lastest version
-  - os: linux
-    env:
-      - LLVM_VERSION=3.8.1
-      - SPECIAL=sanitizer
-    addons:
-      apt:
-        sources: ['ubuntu-toolchain-r-test']
-        packages: g++-6
-    compiler: clang
-    before_script:
-      - make clang_sanitize
-
-  # cppcheck
-
-  - os: linux
-    compiler: gcc
-    env:
-      - COMPILER=g++-4.9
-      - SPECIAL=cppcheck
-    addons:
-      apt:
-        sources: ['ubuntu-toolchain-r-test']
-        packages: [g++-4.9, cppcheck]
-    after_success:
-      - make cppcheck
-
-  # no exceptions
-
-  - os: linux
-    compiler: gcc
-    env:
-      - COMPILER=g++-4.9
-      - SPECIAL=no_exceptions
-    addons:
-      apt:
-        sources: ['ubuntu-toolchain-r-test']
-        packages: [g++-4.9, cppcheck]
-    after_success:
-      - make clean
-      - CPPFLAGS="-DJSON_NOEXCEPTION" make check TEST_PATTERN="-e \"*\""
-
-  # Coveralls (http://gronlier.fr/blog/2015/01/adding-code-coverage-to-your-c-project/)
-
-  - os: linux
-    compiler: gcc
-    addons:
-      apt:
-        sources: ['ubuntu-toolchain-r-test']
-        packages: ['g++-4.9', 'ruby']
-    before_script:
-      - wget http://ftp.de.debian.org/debian/pool/main/l/lcov/lcov_1.11.orig.tar.gz
-      - tar xf lcov_1.11.orig.tar.gz
-      - sudo make -C lcov-1.11/ install
-      - gem install coveralls-lcov
-      - pip install --user cpp-coveralls
-    after_success:
-      - make clean
-      - CXXFLAGS="--coverage -g -O0" CPPFLAGS="-DNDEBUG" make json_unit
-      - test/json_unit "*"
-      - coveralls --build-root test --exclude src/catch.hpp --exclude src/unit-algorithms.cpp --exclude src/unit-allocator.cpp --exclude src/unit-capacity.cpp --exclude src/unit-class_const_iterator.cpp --exclude src/unit-class_iterator.cpp --exclude src/unit-class_lexer.cpp --exclude src/unit-class_parser.cpp --exclude src/unit-comparison.cpp --exclude src/unit-concepts.cpp --exclude src/unit-constructor1.cpp --exclude src/unit-constructor2.cpp --exclude src/unit-convenience.cpp --exclude src/unit-conversions.cpp --exclude src/unit-deserialization.cpp --exclude src/unit-element_access1.cpp --exclude src/unit-element_access2.cpp --exclude src/unit-inspection.cpp --exclude src/unit-iterator_wrapper.cpp --exclude src/unit-iterators1.cpp --exclude src/unit-iterators2.cpp --exclude src/unit-json_patch.cpp --exclude src/unit-json_pointer.cpp --exclude src/unit-modifiers.cpp --exclude src/unit-pointer_access.cpp --exclude src/unit-readme.cpp --exclude src/unit-reference_access.cpp --exclude src/unit-regression.cpp --exclude src/unit-serialization.cpp --exclude src/unit-testsuites.cpp --exclude src/unit-unicode.cpp --include ../src/json.hpp --gcov-options '\-lp' --gcov 'gcov-4.9'
-      - lcov --directory src --directory test/src --capture --output-file coverage.info --rc lcov_branch_coverage=1 --no-external
-      - lcov --remove coverage.info 'test/src/*' --output-file coverage.info --rc lcov_branch_coverage=1
-      - lcov --list coverage.info --rc lcov_branch_coverage=1
-      - coveralls-lcov --repo-token F9bs4Nop10JRgqPQXRcifyQKYhb3FczkS coverage.info
-    env:
-      - COMPILER=g++-4.9
-      - SPECIAL=coveralls
-
-  # Coverity (only for branch coverity_scan)
-
-  - os: linux
-    compiler: clang
-    before_install: echo -n | openssl s_client -connect scan.coverity.com:443 | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' | sudo tee -a /etc/ssl/certs/ca-certificates.crt
-    addons:
-      coverity_scan:
-        project:
-          name: "nlohmann/json"
-          description: "Build submitted via Travis CI"
-        notification_email: niels.lohmann@gmail.com
-        build_command_prepend: "make clean"
-        build_command: "make"
-        branch_pattern: coverity_scan
-    env:
-      - LLVM_VERSION=3.6.0
-      - SPECIAL=coverity
-
-  # OSX / Clang
-
-  - os: osx
-    osx_image: xcode6.4
-
-  - os: osx
-    osx_image: xcode7.3
-
-  - os: osx
-    osx_image: xcode8
-
-  - os: osx
-    osx_image: xcode8.1
-
-  - os: osx
-    osx_image: xcode8.2
-
-  - os: osx
-    osx_image: xcode8.3
-
-  - os: osx
-    osx_image: xcode9
-
-  # Linux / GCC
-
-  - os: linux
-    compiler: gcc
-    env: COMPILER=g++-4.9
-    addons:
-      apt:
-        sources: ['ubuntu-toolchain-r-test']
-        packages: g++-4.9
-
-  - os: linux
-    compiler: gcc
-    env: COMPILER=g++-5
-    addons:
-      apt:
-        sources: ['ubuntu-toolchain-r-test']
-        packages: g++-5
-
-  - os: linux
-    compiler: gcc
-    env: COMPILER=g++-6
-    addons:
-      apt:
-        sources: ['ubuntu-toolchain-r-test']
-        packages: g++-6
-
-  - os: linux
-    compiler: gcc
-    env: COMPILER=g++-7
-    addons:
-      apt:
-        sources: ['ubuntu-toolchain-r-test']
-        packages: g++-7
-
-  - os: linux
-    compiler: gcc
-    env:
-      - COMPILER=g++-7
-      - CXXFLAGS=-std=c++17
-    addons:
-      apt:
-        sources: ['ubuntu-toolchain-r-test']
-        packages: g++-7
-
-  # Linux / Clang
-
-  - os: linux
-    env: LLVM_VERSION=3.6.0
-    compiler: clang
-
-  - os: linux
-    env: LLVM_VERSION=3.6.1
-    compiler: clang
-
-  - os: linux
-    env: LLVM_VERSION=3.6.2
-    compiler: clang
-
-#  - os: linux
-#    env: LLVM_VERSION=3.7.0
-#    compiler: clang
-
-#  - os: linux
-#    env: LLVM_VERSION=3.7.1
-#    compiler: clang
-
-  - os: linux
-    env: LLVM_VERSION=3.8.0
-    compiler: clang
-
-  - os: linux
-    env: LLVM_VERSION=3.8.1
-    compiler: clang
-
-#  - os: linux
-#    addons:
-#      apt:
-#        sources: llvm-toolchain-trusty-3.9
-#        packages: clang-3.9
-#    env: COMPILER=clang++-3.9
-#
-#  - os: linux
-#    addons:
-#      apt:
-#        sources: llvm-toolchain-trusty-4.0
-#        packages: clang-4.0
-#    env: COMPILER=clang++-4.0
-#
-#  - os: linux
-#    addons:
-#      apt:
-#        sources: llvm-toolchain-trusty
-#        packages: clang-5.0
-#    env: COMPILER=clang++-5.0
-
-#####################
-# installation step #
-#####################
-
-# set directories to cache
-cache:
-  directories:
-    - ${TRAVIS_BUILD_DIR}/deps/llvm-3.6.2
-    - ${TRAVIS_BUILD_DIR}/deps/llvm-3.6.1
-    - ${TRAVIS_BUILD_DIR}/deps/llvm-3.6.0
-    - ${TRAVIS_BUILD_DIR}/deps/llvm-3.7.0
-    - ${TRAVIS_BUILD_DIR}/deps/llvm-3.7.1
-    - ${TRAVIS_BUILD_DIR}/deps/llvm-3.8.0
-    - ${TRAVIS_BUILD_DIR}/deps/llvm-3.8.1
-
-
-install:
-  # create deps dir if not existing
-  - DEPS_DIR="${TRAVIS_BUILD_DIR}/deps"
-  - mkdir -p ${DEPS_DIR}
-
-  # make sure CXX is correctly set
-  - if [[ "${COMPILER}" != "" ]]; then export CXX=${COMPILER}; fi
-
-  # get CMake (only for systems with brew - macOS)
-  - |
-     if [[ !(-x $(which cmake)) && (-x $(which brew)) ]]; then
-       brew update
-       brew install cmake
-       cmake --version
-     fi
-
-  # install LLVM/clang when LLVM_VERSION is set
-  - |
-     if [[ "${LLVM_VERSION}" != "" ]]; then
-       LLVM_DIR=${DEPS_DIR}/llvm-${LLVM_VERSION}
-       if [[ -z "$(ls -A ${LLVM_DIR})" ]]; then
-         travis_retry wget --quiet https://cmake.org/files/v3.6/cmake-3.6.1.tar.gz
-         tar xfz cmake-3.6.1.tar.gz
-         (cd cmake-3.6.1 && ./configure --prefix=${LLVM_DIR}/cmake && make install)
-         export PATH="${LLVM_DIR}/cmake/bin:${PATH}"
-         LLVM_URL="http://llvm.org/releases/${LLVM_VERSION}/llvm-${LLVM_VERSION}.src.tar.xz"
-         LIBCXX_URL="http://llvm.org/releases/${LLVM_VERSION}/libcxx-${LLVM_VERSION}.src.tar.xz"
-         LIBCXXABI_URL="http://llvm.org/releases/${LLVM_VERSION}/libcxxabi-${LLVM_VERSION}.src.tar.xz"
-         CLANG_URL="http://llvm.org/releases/${LLVM_VERSION}/clang+llvm-${LLVM_VERSION}-x86_64-linux-gnu-ubuntu-14.04.tar.xz"
-         mkdir -p ${LLVM_DIR} ${LLVM_DIR}/build ${LLVM_DIR}/projects/libcxx ${LLVM_DIR}/projects/libcxxabi ${LLVM_DIR}/clang
-         travis_retry wget --quiet -O - ${LLVM_URL}      | tar --strip-components=1 -xJ -C ${LLVM_DIR}
-         travis_retry wget --quiet -O - ${LIBCXX_URL}    | tar --strip-components=1 -xJ -C ${LLVM_DIR}/projects/libcxx
-         travis_retry wget --quiet -O - ${LIBCXXABI_URL} | tar --strip-components=1 -xJ -C ${LLVM_DIR}/projects/libcxxabi
-         travis_retry wget --quiet -O - ${CLANG_URL}     | tar --strip-components=1 -xJ -C ${LLVM_DIR}/clang
-         (cd ${LLVM_DIR}/build && cmake .. -DCMAKE_INSTALL_PREFIX=${LLVM_DIR}/install -DCMAKE_CXX_COMPILER=clang++)
-         (cd ${LLVM_DIR}/build/projects/libcxx && make install -j2)
-         (cd ${LLVM_DIR}/build/projects/libcxxabi && make install -j2)
-       fi
-       export CXXFLAGS="-nostdinc++ -isystem ${LLVM_DIR}/install/include/c++/v1"
-       export LDFLAGS="-L ${LLVM_DIR}/install/lib -l c++ -l c++abi"
-       export LD_LIBRARY_PATH="${LD_LIBRARY_PATH}:${LLVM_DIR}/install/lib"
-       export PATH="${LLVM_DIR}/clang/bin:${PATH}"
-     fi
+        sources: ['ubuntu-toolchain-r-test', 'llvm-toolchain-precise-3.8']
+        packages: ['g++-6', 'clang-3.8']
 
 ################
 # build script #
 ################
 
 script:
+  # make sure CXX is correctly set
+  - if [[ "${COMPILER}" != "" ]]; then export CXX=${COMPILER}; fi
+
   # show OS/compiler version
   - uname -a
   - $CXX --version
@@ -324,11 +53,3 @@ script:
   - cmake .. && cmake --build . --config Release -- -j4
   - ctest -C Release -V
   - cd ..
-
-  # check if homebrew works (only checks develop branch)
-  - if [ `which brew` ]; then
-    brew update ;
-    brew tap nlohmann/json ;
-    brew install nlohmann_json --HEAD ;
-    brew test nlohmann_json ;
-    fi