Automate the process to cut the release

[tusharnt]

• [ ] Use Releases API to automate some of the steps that are done manually while cutting the release - https://developer.github.com/v3/repos/releases/
• [ ] Automate upload of release binaries to bintray - https://bintray.com/docs/api/
• [ ] Automate upload of the managed plugin to docker store - https://docs.docker.com/docker-store/
• [ ] Automate the content on StorageHub to reflect the latest documentation- tracked by #1965
• [ ] Automate impersonate as a customer to download vib and plugins after the release is cut and perform basic/upgrade testing.

[shuklanirdesh82]

we shall reopen if needed in future.