Add travis-ci configuration
Disable Git submodules on Travis

See http://docs.travis-ci.com/user/build-configuration/#Git-Submodules
Update build status badge to reflect Travis CI
Produce clean Gradle console output in Travis builds

http://stackoverflow.com/questions/17942819/how-can-i-get-clean-gradle-output-on-travis-ci
Send HipChat notifications from Travis CI build

See http://docs.travis-ci.com/user/encryption-keys
Add secure environment variables and deploy command

Per instructions at:

 - http://docs.travis-ci.com/user/build-configuration/#Secure-environment-variables
 - http://www.gradle.org/docs/current/userguide/userguide_single.html#sec:gradle_properties_and_system_properties