Cache gems on S3 for Travis to speed up test runs.

Uses the script from this repo: https://github.com/Fingertips/WAD
Merge pull request #531 from codeforamerica/cache-gems-on-travis

Cache gems on S3 for Travis to speed up test runs.
Hotfix to fix bug in JS async plugin syntax

The asset pipeline optimizer didn’t like the Google URL broken across
two lines, causing the async plugin not to load properly. This commit
formats the URL to fit on one line.
Merge pull request #532 from codeforamerica/hotfix-async-plugin

Hotfix to fix bug in JS async plugin syntax
Fixes #495 - Adds input clear button

- Adds search input manager for handling input clear button—little (x).
- Disables autocomplete because field highlight color can’t be
overridden.
- Removes unused data-list attributes.
- Adds tests for clearing the input fields.
Refactors class names

- Normalized button and form id/class names using the specificity
principle.
- Removes unused classes from submit/reset buttons.