Bumping Version to 1.5.1

Merge pull request airbnb#127 from airbnb/btw/1.5.0

Updating to 1.5.0

Merge pull request airbnb#121 from airbnb/btw/npmUpdate

Update Static Library Build

Bumping Version

Merge pull request airbnb#76 from airbnb/btw/cartUpdate

Fixed header issue with Carthage

Update lottie-ios.podspec

Bumping podspec vesrion

Merge branch 'master' of github.com:airbnb/lottie-ios