Fix application's GAV coordinates

To simplify version management, set versions via dependencyManagement.
Enable Travis-CI

Try Travis-CI [1] as a continuous integration.

[1] http://travis-ci.org/
[2] https://github.com/leviwilson/android-travis-ci-example
[3] http://levi-wilson.blogspot.com/2012/06/maven-android-travis-ci-and-more.html
Tweak default Travis CI's build lifecycle for Maven

- Don't do anything during 'install' step;
- Running 'mvn install' will compile sources, run unit and integration
  tests as defined by Maven's lifecycle.

Create AVD and start emulator with this device
Fix build
Install Android API 15, according to POM
Create an SD card

Export feature requires SD card