CMake VERSION needs to be bumped in master

[Joshua S Brown]

Currently, master is using some variables that only appear to be available after 3.14 e.g. CMAKE_INSTALL_BINDIR

[Christoph Junghans]

There variables get defined by GNUInstallDirs.cmake for earlier versions of CMake, see:
https://github.com/Kitware/CMake/blob/v3.10.0/Modules/GNUInstallDirs.cmake#L36