Release TeraFlowSDN NSC 7.0

Release Notes:

• #15 (closed): New IPoWDM realizer
• #23 (closed): Resolve bug: templates are not dumped when flag is set to true
• #24 (closed): Enhance RESTCONF-based NBI
• #25 (closed): Improve mapping of slice requests
• #26 (closed): FRR topology Use Case
• #27 (closed): Authentication-based API