releases contain snapshot components

[jgrivolla]

Some components (see e.g. https://github.com/dkpro/dkpro-core/blob/de.tudarmstadt.ukp.dkpro.core-1.9.2/dkpro-core-io-cermine-gpl/pom.xml) appear to have SNAPSHOT versions even within DKPro releases (at least in 1.9.0, 1.9.1 and 1.9.2). This leads to problems with gitflow which rejects SNAPSHOTS even for components that are only seen through DependencyManagement (when using the JGit Flow Maven Plugin, according to @Jibun).

This seems to be the case for at least dkpro-core-io-nyt-asl, org-dkpro-core-lancaster-asl, and dkpro-core-io-cermine-gpl.