#274 - small tweaks in cmake

[JeffGarland]

When reviewing the take_before repo I found some issues.

[JeffGarland]

3.28 is minimum for modules -- we should have that as minimum now

[coveralls]

coverage: 100.0%. remained the same
when pulling df40a6d on 274-exemplar-various-updates-cmake-etc
into 2fd62a5 on main.

[JeffGarland]

Also, we seem to have an error here -- after repo clone an cookie cutter

-- Detecting CXX compile features - done
CMake Error at src/beman/char_conversion/CMakeLists.txt:19 (find_package):
  By not providing "Findbeman-install-library.cmake" in CMAKE_MODULE_PATH
  this project has asked CMake to find a package configuration file provided
  by "beman-install-library", but CMake did not find one.

  Could not find a package configuration file provided by
  "beman-install-library" with any of the following names:

    beman-install-libraryConfig.cmake
    beman-install-library-config.cmake

  Add the installation prefix of "beman-install-library" to CMAKE_PREFIX_PATH
  or set "beman-install-library_DIR" to a directory containing one of the
  above files.  If "beman-install-library" provides a separate development
  package or SDK, be sure it has been installed.

[wusatosi]

Can you provide more context on what this is?