Fix travis build failing because of missing license agreement

[dadosch]

But it fails anyway at an other point:

net.osmtracker.test.gpx.ExportTrackTaskTest > test[test(AVD) - 4.4.2] FAILED 
	junit.framework.AssertionFailedError
	at net.osmtracker.test.gpx.ExportTrackTaskTest.test(ExportTrackTaskTest.java:76)
:app:connectedDebugAndroidTest FAILED
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':app:connectedDebugAndroidTest'.
> There were failing tests. See the report at: file:///home/travis/build/dadosch/osmtracker-android/app/build/reports/androidTests/connected/index.html