Upgrade gitlab-styles to 10.0

Description

Upgrade gitlab-styles to 10.0.0 and auto-correct all RuboCop offenses.

Offenses fixed

$ bundle exec rubocop --format offenses
 39/39 files |======================================= 100 ========================================>| Time: 00:00:00

34  RSpec/VerifiedDoubles
8   RSpec/BeEq
6   Lint/UnusedMethodArgument
2   Lint/AmbiguousOperatorPrecedence
2   RSpec/ExpectChange
1   RSpec/IdenticalEqualityAssertion
1   Style/QuotedSymbols
--
54  Total in 11 files

Related Issues

Suggested version bump

• Major (backwards incompatible changes)
• Minor (backwards compatible changes)
• Patch (API compatible changes)

Checklist

• Tests have been added or updated to cover any changes in behavior
• This does not change the API to consume this library, or a suggested version bump has been provided
• The CHANGELOG.md has been updated
• No new runtime dependencies have been introduced