Remove retrolambda from project, to add Play services.

Play services are required to show map.
Show a map on location list item tap.
Show locations on map
Add Play services on Travis and change Play minimum version for Travis
Add About Activity w/ Lorem Ipsum text
Fixes for Travis.

Undefine Play services version, so latest found will be used.
Remove unused library from .travis.yml.
Merge pull request #16 from CloudNiner/feature/about-activity

Add About Activity w/ Lorem Ipsum text
Revert Play services version for Travis
Merge branch 'feature/add-locations-map' into develop
Fix merge conflicts
Fix merge
Toggle marker visibility with map button bar
Move padding for list view so map view isn't padded
Merge pull request #17 from flibbertigibbet/feature/add-map-buttons

Toggle marker visibility with map button bar
Add unstyled candidate detail fragment
Add tests for Candidate/SocialMediaChannel models