Version info data handled for OpenStackWorkloadStats. If master node
updated and the version info in InstallationStructure changed we have
correct version info in OSWLs stats report.
Fixes in collector:
- version_info added to DB model
- version_info added to API protocol
- tests for version_info added
Fixes in analytics:
- version_info added to DB model
- version_info fields added to CSV
- field installation structure release info removed from CSV
- version_info building on the fly for old OSWLs added
Partial-Bug: #1525902
Change-Id: I27d9d65517b4d5a7c6125b889fb0d1ba1ea213cf