Template for cross-platform C++ project.
CMake 3.17.0 is a build system.
Catch2 and Trompeloeil used as testing and mocking frameworks.
Travis integration using CentOS 8 docker image with GCC 9 or Clang 8.
AppVeyor integration using Visual Studio 2019 image with MSVC_x64 and Clang 10 compilers.