Update required cmake version to 3.7
Update required cmake version to 3.7

This fixes the bug described in #129 in cmake in https://gitlab.kitware.com/cmake/cmake/-/issues/14201 where cuda_add_library would not pick up the include files as given by target_include_directories.
This was fixed in cmake version 3.7, and therefore the fix simply increases our required cmake version.

aniabrown/QUEST,aniabrown/QUEST,aniabrown/QUEST