- Add prefix header
- Include catch.hpp
- Include json.hpp
- Replace private with public for all json_unit files
- Move `unit.cpp` to an object library
- cotire issue: strip whitespace from CMAKE_INCLUDE_SYSTEM_FLAG_CXX
- define the project's version in the cmake listfile
- create a config and config version file for the cmake package
- install the json.hpp file and the package's targets, config and
config version files