Add initial Travis-CI support

Refer to example - https://github.com/pestrada/android-tdd-playground
Add Travis build status to README.md
Testing debug TravisCI build
Update buildToolsVersion to '19.0.1'
Revert back to connectedInstrumentTest for TravisCI
Correct build tool version to 19.0.1 in TravisCI config
Update to Travis config to build tools for android 4.4.2
Update dagger-injections library to use build tools 19.0.1
Update Proguard configuration to ignore unimportant Dagger warnings
Improve Proguard comment
Remove direct Gradle installation

Travis build should use the Gradle wrapper
Add wait_for_emulator script for Travis
Echo $TRAVIS_TEST_RESULT from Travis CI
Merge pull request #52 from peter-tackage/travis-support

Add initial Travis-CI support