After installing Rubocop 0.71, I received this warning:
Rails cops will be removed from RuboCop 0.72. Use the `rubocop-rails` gem instead.
This commit follows these instructions.
[ci skip]
In Rails 5, the schema layer was updated so that indexes could be
created on expressions rather that simply columns. Update
`have_db_index` so that you can test for this.
More reading: <edc2b77187>
The original Rubocop configuration was copied from other thoughtbot
projects. Of course, Rubocop comes with its own set of default settings.
Therefore, we don't need to re-specify settings that it already has --
we only need to specify the ones that we're overriding.
Besides this, Rubocop isn't even in the Gemfile, so even though Hound
runs on GitHub automatically, it'd be nice to spot style issues as you
are editing files.
Given this, this commit simplifies the Rubocop configuration and also
adds Rubocop to the Gemfile so that you can configure your editor to
lint files as you are editing them.
