VOLTHA Release: voltctl

Release Builds howto:

Increment the VERSION file to a major or minor point release.
Initiate a jenkins job to build components (WIP: searching).
- repo::voltctl, Gerrit example: 33551.
- At least two jenkins jobs need to run:
  - version-tag_wildcard
  - github-release_voltctl
Verify git tags
- A SemVer tag was created (vee prefix v{semver} signifies a golang package).
- Verify the package(v1.8.0) contains more than just source archives (gz, zip): - The tags page index lacks Notes and Downloads links.
- A valid package(v1.7.6) will include:
  - The tags page index contains Notes and Downloads links.
  - A checksum file
  - Versioned voltctl binaries for several platforms.
  - Source code bundles (tar.gz and zip).
Released version will be consumed by jenkins installer vars/installVoltctl.groovy.

installVoltctl.groovy depends on github/releases/latest for versioned release information.
To generate a release commit changes to repo::voltctl:
- Modify VERSION file major/minor numbers for the upcoming release.
- Remove any -dev or patch modifiers.
- Create a pull request for review.
- Changes will be published when the jenkins job github-release-voltctl is run.
Verify the release version contains a checksum file:
- checksum.SHA256
- voltctl-1.7.6-darwin-amd64
- voltctl-1.7.6-linux-amd64
- voltctl-1.7.6-linux-arm64
- voltctl-1.7.6-windows-amd64
- Source code (zip)
- Source code (tar.gz)