Updates capybara to 2.4.4

Updates capybara to 2.4.4 from 2.4.1
Updates ffi to 1.9.6

- Updates listen gem ffi gem sub-dependency to 1.9.6 from 1.9.3. Spring
uses listen but does not currently support version 2.x.
- Adds code comment to gemfile noting why listen gem is present.
Updates quiet_assets to 1.0.3
Update webmock to 1.20.4
Updates yard to 0.8.7.6
Update chunky_png to 1.3.3

chunky_png is used by compass-rails.
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
Merge pull request #698 from codeforamerica/upgrade-chunky_png

Update chunky_png to 1.3.3
Merge pull request #697 from codeforamerica/upgrade-yard

Updates yard to 0.8.7.6
Merge pull request #696 from codeforamerica/upgrade-webmock

Update webmock to 1.20.4
Update vcr to 2.9.3
Merge pull request #693 from codeforamerica/upgrade-quiet_assets

Updates quiet_assets to 1.0.3
Merge pull request #692 from codeforamerica/upgrade-listen

Updates ffi to 1.9.6
Merge pull request #688 from codeforamerica/upgrade-rubocop

Update rubocop to 0.27.1
Merge pull request #695 from codeforamerica/upgrade-vcr

Update vcr to 2.9.3
Updates rspec-rails to 3.1.0