Overcommit 0.30.0

Fixes a showstopper bug that prevented the use of existing hook scripts when invoked via the --run flag, along with some new hooks and other bug fixes.

New Features

• Add Dogma pre-commit hook to lint Elixir files with
  dogma files
• Add Minitest pre-push hook to run Minitest tests
• Add RailsBestPractices pre-commit hook which lints code with
  rails_best_practices

Bug Fixes

• Fix --run flag to not block reading STDIN when using existing hook scripts
• Fix RuboCop pre-commit hook to fail when RuboCop version specified by
  Bundler context is not available
• Fix TextWidth commit-msg hook to not include newline characters in
  calculated width