chore: add automatic github release

[gkatsev]

This will automatically do a github release with the correct changelog entry and the built zip file.
If a publish is made with --tag next it will mark the release as a pre-release.

To use, just add VJS_GITHUB_USER and VJS_GITHUB_TOKEN env variables as part of the publish command:

$ VJS_GITHUB_USER=gkatsev VJS_GITHUB_TOKEN=test_token npm publish --tag next

[misteroneill]

LGTM