Delete unused files.

This commit deletes 2 stub files, App.java and AppTest.java.
Merge pull request #21 from m1ch1/cleanup

Delete unused files.
Publish Maven artifacts after each successful build.
Merge pull request #22 from m1ch1/maven

Publish Maven artifacts after each successful build.
Enable publishing Maven artifacts.
Merge pull request #23 from m1ch1/master

Enable publishing Maven artifacts.
Specify altDeploymentRepository for mvn deploy.
Merge pull request #24 from m1ch1/master

Specify altDeploymentRepository for mvn deploy.
Fix the maven target from site to deploy.
Merge pull request #25 from m1ch1/master

Fix the maven target from site to deploy.
Make the Maven repository path shorter.
Merge pull request #26 from m1ch1/master

Make the Maven repository path shorter.
Avoid running mvn command twice.
Merge pull request #27 from m1ch1/master

Avoid running mvn command twice.
Only deploy oraclejdk7 build from master.
Merge pull request #28 from m1ch1/master

Only deploy oraclejdk7 build from master.
Use logback for logging.

Use logback to write unit test log messages to stdout, and
configure the surefire plugin to redirect stdout to files
under target/surefire-reports.
Merge pull request #30 from m1ch1/master

Use logback for logging.
Use FindBugs Maven plugin and fix FindBugs errors.

Run findbugs:check at the before_script phase of the Travis build.
The current version of findbugs-maven-plugin does not work with Java
1.8, so the check is not included in the maven compile phase for now.