Release bpgenerator 1.7.1

Release bpgenerator 1.7.1

Blueprint generator is now a Spring project consisting of:
- blueprint-generator-common - Spring library
- blueprint-generator-onap - ONAP specific Spring library
- blueprint-generator-onap-executable - standalone, ONAP
  specific Spring command-line application

Changes:
- Update relationshipsType and feedNode values in DmaapNode
- Add useExisting property to Dmaap Feed Node
- Refactor bpgen using Spring
- Fix yaml fixes difference for files and string bp's

Issue-ID: DCAEGEN2-2459
Issue-ID: DCAEGEN2-2460
Issue-ID: DCAEGEN2-2472
Issue-ID: DCAEGEN2-2489
Signed-off-by: Remigiusz Janeczek <remigiusz.janeczek@nokia.com>
Change-Id: I95ed13d4436a57b5c194ba435745a7a507696a19