Fixes #335 - styles geolocation button.

- Updates style of geolocation “Services near me” button to use small
button style. Also moves the geolocation button on the homepage from
the lower-right corner to under the search button.
- Adjusts the height of the language-box area to reduce the overall
height slightly.
- Adjusts responsive styles to accommodate move of geolocate button.
- Adjusts location manager to use main search form, instead of location
form (also removes location form because it’s no longer needed as the
geolocate button is now located in the main form).
- Updates cassettes to include location in URL parameters.
Merge pull request #392 from codeforamerica/335-geolocate-btn-style

Fixes #335 - styles geolocation button.