Recent versions introduce the `Layout/SpaceAroundMethodCallOperator`,
which we are going to use. We aren't upgrading to the latest rubocop
version because it conflicts with the version of Capybara we're using
and because it isn't supported by Hound.
Some rules have been renamed:
Layout/IndentAssignment is now Layout/AssignmentIndentation
Layout/IndentHeredoc is now Layout/HeredocIndentation
Layout/LeadingBlankLines is now Layout/LeadingEmptyLines
Layout/Tab is now Layout/IndentationStyle
Layout/TrailingBlankLines is now Layout/TrailingEmptyLines
Lint/StringConversionInInterpolation is now Lint/RedundantStringCoercion
Metrics/LineLength is now Layout/LineLength
Note after upgrading we get a new "offense" in the `StartWith` rule, so
we're changing the code in order to fix it.