Update better_errors to 2.0.0
Merge pull request #689 from codeforamerica/upgrade-better_errors

Update better_errors to 2.0.0
Updates capybara to 2.4.4

Updates capybara to 2.4.4 from 2.4.1
Merge pull request #690 from codeforamerica/upgrade-capybara

Updates capybara to 2.4.4
Update rubocop to 0.27.1

- Updates rubocop to 0.27.1 from 0.24.1.
- Fixes new rubocop offenses.
Updates cassettes