Selenium tests

Running tests locally with local Selenium
- Configure environment
```
export FEC_SELENIUM_DRIVER="chrome"
```

Running tests locally with Sauce

Configure Sauce OS, browser, version in local environment

export FEC_SELENIUM_DRIVER="remote"
export FEC_SAUCE_PLATFORM="Mac OS X 10.9"
export FEC_SAUCE_DRIVER="chrome"
export FEC_SAUCE_VERSION="39"

Running tests on Travis
- Secure Sauce Labs credentials
  - gem install travis
  - travis encrypt SAUCE_USERNAME=<username>
  - travis encrypt SAUCE_ACCESS_KEY=<access key>
  - Add encrypted keys to .travis.yml
- Add OS / browser / version to Travis build matrix
```
matrix:
    - FEC_SAUCE_PLATFORM="Mac OS X 10.9" FEC_SAUCE_BROWSER=chrome
    - FEC_SAUCE_BROWSER=firefox
```