From d3496347fcd1382896fca3aaf78a0d803c2f52ec Mon Sep 17 00:00:00 2001
From: Niels Lohmann <mail@nlohmann.me>
Date: Sun, 9 Jul 2017 12:19:14 +0200
Subject: [PATCH] :construction_worker: removing Clang 3.9 and 4.0

These versions are still not working properly: https://travis-ci.org/nlohmann/json/jobs/251675281
---
 .travis.yml | 26 +++++---------------------
 1 file changed, 5 insertions(+), 21 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index ec1cbeb1..530ef434 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -183,17 +183,17 @@ matrix:
 
   - os: linux
     compiler: gcc
-    env:
-      - COMPILER=g++-6
-      - CXXFLAGS=-std=c++1z
+    env: COMPILER=g++-7
     addons:
       apt:
         sources: ['ubuntu-toolchain-r-test']
-        packages: g++-6
+        packages: g++-7
 
   - os: linux
     compiler: gcc
-    env: COMPILER=g++-7
+    env:
+      - COMPILER=g++-7
+      - CXXFLAGS=-std=c++17
     addons:
       apt:
         sources: ['ubuntu-toolchain-r-test']
@@ -229,22 +229,6 @@ matrix:
     env: LLVM_VERSION=3.8.1
     compiler: clang
 
-  - os: linux
-    compiler: clang
-    env: COMPILER=clang++-3.9
-    addons:
-      apt:
-        sources: ['ubuntu-toolchain-r-test', 'llvm-toolchain-trusty-3.9']
-        packages: clang-3.9
-
-  - os: linux
-    compiler: clang
-    env: COMPILER=clang++-4.0
-    addons:
-      apt:
-        sources: ['ubuntu-toolchain-r-test', 'llvm-toolchain-trusty-4.0']
-        packages: clang-4.0
-
 #  - os: linux
 #    addons:
 #      apt: