(PE-4989) Add tests to ensure settings are present

Add back in tests from the ini file module to ensure settings
are present and modify them to apply to a .conf file instead
of a .ini file
(PE-4989) Add ability to ensure setting is absent

Add the ability to ensure a setting is absent from a .conf
file. Add tests for this functionality.
(PE-4989) Remove unnecessary implementation files

Remove unnecessary implementation files that were left over
from the .ini module.