Elixir comes with its own formatter since version 1.6.
I think it's better to use language's default tooling, instead of relying on external dependencies.
Hence, I'm dropping credo and introducing the formatter.
I wanted to add mix format --check-formatted to Travis CI without dropping older versions of Elixir from the matrix, so I had to add a test/formatter script, which runs the formatter only if it's found.
- Add the
.formatter.exsfile. - Add formatter to Travis CI.
- Fix formatter's offences.
- Get rid of
credo.