Revert "mvn gitflow:release setting POM version to 0.5"

This reverts commit 1ba196305a9614f2df621e98fbbd87a8383db4f0.
mvn gitflow:release setting POM version to 0.6-SNAPSHOT
Merge branch 'hotfix/0.5.1' into develop

Conflicts:
	pom.xml
Use 0.4-SNAPSHOT of jgitflow
Updated caveat after clean up.
License & Copyright info.
Rename release goal release-start.
Tidy output.
Readme change.
Added link to new plugin.
Improve instructions.
mvn gitflow:release setting POM version to 0.6
Merge branch 'release/0.6'