Delete duplicated json files: they were move to build-tools but not delete from engine/schema
Updating travis CI configuration to use android-19 API. Resolve build problems in #274
Merge pull request #271 from angeldelblanco/delete-duplicate-json

Delete duplicated json files:
Merge pull request #275 from imartinezortiz/travis-android-fix

Updating travis CI configuration to solve build problems in #274