Add proper release steps

[MarkusTiede]

Add

• build 0.0.7 release of current master HEAD
• description how to release

[MarkusTiede]

Requires baloise/open-source#43

[MarkusTiede]

baloise/repository-template-java#4 demonstrates how to do this for our template repository. IMHO this should be transferrable 1:1 to TAF.

[MarkusTiede]

@arburk - thanks for providing #32. I think in addition to that we should make sure that

• we release one of the upcoming versions of TAF here
• make sure that it's working to consume it internally via our nexus artefact repository mirroring.

@seejaybee / @bsolar17 what do you think: does this makes sense?

[MarkusTiede]

• for SNAPSHOTS: make sure that it's working to consume it internally via our nexus artefact repository mirroring