0.5.2 release

• Package improvements
• TestFX 4.0.15-alpha
• Prevent conflicts with Commons by shading it
• Continuing to use awt robot with library
• Moved test app to test code
• Surefire update because of https://issues.apache.org/jira/browse/SUREFIRE-1588 / https://stackoverflow.com/questions/53010200/maven-surefire-could-not-find-forkedbooter-class
• Add keyword Launch Swing Application In Separate Thread
• Get FxRobotContext from the active sessionRobot in TestFxAdapter
• Bug #7 fixed