Update powermock to 1.5.6
Use stable version of Log4J2 (2.0.2)
Use maven deploy plugin 2.8.2
Merge pull request #36 from SvenBunge/log4j2-stable

Fix #35: Use stable version of Log4J2 (2.0.2)
Merge pull request #39 from SvenBunge/mvndeployplugin

Use maven deploy plugin 2.8.2
Merge pull request #38 from SvenBunge/Powermock156

Update powermock to 1.5.6