Add formatting, xref and dialyzer

[carlosedp]

No description provided.

[carlosedp]

Adding config to rebar.conf makes the tests fail:

===> Performing EUnit tests...
FF
Failures:

  1) dia_tests:compile_only_test_/0
     Failure/Error: ?assertCmdStatus(0, "rebar3 diameter compile")
       expected: status 0
            got: status 1
     %% eunit_proc.erl:570:in `eunit_proc:run_group/2`
     Output: 
     Output: 
  2) dia_tests:compare_test/0
     Failure/Error: {error,
                        {badmatch,{error,enoent}},
                        [{dia_tests,compare_files,2,
                             [{file,
                                  "/home/runner/work/rebar3_diameter_compiler/rebar3_diameter_compiler/test/dia_tests.erl"},
                              {line,190}]},
                         {dia_tests,compare_files,0,
                             [{file,
                                  "/home/runner/work/rebar3_diameter_compiler/rebar3_diameter_compiler/test/dia_tests.erl"},
                              {line,165}]},
                         {eunit_test,'-mf_wrapper/2-fun-0-',2,
                             [{file,"eunit_test.erl"},{line,273}]},
                         {eunit_test,run_testfun,1,
                             [{file,"eunit_test.erl"},{line,71}]},
                         {eunit_proc,run_test,1,
                             [{file,"eunit_proc.erl"},{line,531}]},
                         {eunit_proc,with_timeout,3,
                             [{file,"eunit_proc.erl"},{line,356}]},
                         {eunit_proc,handle_test,2,
                             [{file,"eunit_proc.erl"},{line,514}]},
                         {eunit_proc,tests_inorder,3,
                             [{file,"eunit_proc.erl"},{line,456}]}]}
     Output: 

Pending:
  undefined
    %% Unknown error: {abort,
                   {setup_failed,
                       {error,
                           {badmatch,{error,enoent}},
                           [{dia_tests,setup_create_dia,2,
                                [{file,
                                     "/home/runner/work/rebar3_diameter_compiler/rebar3_diameter_compiler/test/dia_tests.erl"},
                                 {line,48}]},
                            {dia_tests,'-setup_create/4-lc$^0/1-0-',2,
                                [{file,
                                     "/home/runner/work/rebar3_diameter_compiler/rebar3_diameter_compiler/test/dia_tests.erl"},
                                 {line,40}]},
                            {dia_tests,setup_create,4,
                                [{file,
                                     "/home/runner/work/rebar3_diameter_compiler/rebar3_diameter_compiler/test/dia_tests.erl"},
                                 {line,40}]}]}}}


Finished in 0.569 seconds
3 tests, 2 failures, 1 cancelled

I think it might be related to how the tests are run (on a git branch and etc). It only happens after you commit rebar.config.
Could you take a look at this @ebengt / @albertored on how the test could be "fixed"?

[ebengt]

Adding the test was complicated.
I will take a look, but it might take a while.