Update README.md
Dispatch to main queue
Update version to 2.2.1
Actually start and stop recording location changes
Remove unused code from example

To avoid confusion
Merge pull request #70 from sandstrom/patch-2

Remove unused code from example
Update CONTRIBUTORS
Add config option to enable push on launch
Add migration guide
Update android library
Bump version to 2.3.0, update changelog
Migration guide typos
Merge pull request #72 from urbanairship/Release2.3.0

Release2.3.0