Creates jira release version for a train iteration if not present. Creates release tickets in Jira and GitHub if not present. Added pre-release verification that the release ticket is present and all other tickets are closed. Allow singular ticket and release version creation. Add integration tests using WireMock. Add command to self-assign release tickets.
Added CLI commands:
* jira releasetickets
* jira create releasetickets
* jira self-assign releasetickets
* jira create releaseversions
* github tickets
* github releasetickets
* github create releaseversions
* github create releasetickets
Original pull request: #14.
9944848d81