Act on non_reversible_form as an exception to atom naming conventions

[paulo-ferraz-oliveira]

Closes #344.

@elbrujohalcon, not really sure we should make this more explicit with a test (?)

[elbrujohalcon]

A test would be nice, but we can merge the PR as-is if you like, too.

[paulo-ferraz-oliveira]

I'll update the existing test with a simple thing.

Edit (for b341dbc):

Before

%%% style_SUITE ==> {{badmatch,[#{info => [[],-1,"^^[a-z]([a-zA-Z0-9@]*_?)*(_SUITE)?$"],
              message =>
                  "Atom ~p on line ~p does not respect the format defined by the regular expression '~p'.",
              line_num => -1}]},
 [{style_SUITE,verify_atom_naming_convention,1,
               [{file,"/Users/paulo/Development/contrib/elvis_core/test/style_SUITE.erl"},
                {line,1299}]},
  {test_server,ts_tc,3,[{file,"test_server.erl"},{line,1794}]},
  {test_server,run_test_case_eval1,6,[{file,"test_server.erl"},{line,1303}]},
  {test_server,run_test_case_eval,9,[{file,"test_server.erl"},{line,1235}]}]}

After

%%% style_SUITE: .

[paulo-ferraz-oliveira]

If the test passes I'm merging with your approval.

[paulo-ferraz-oliveira]

GitHub 3.2.4: https://github.com/inaka/elvis_core/releases/tag/3.2.4
Hex 3.2.4: https://hex.pm/packages/elvis_core/3.2.4