fix(package): update travis-deploy-once to version 4.0.0

fix: typo in EINVALIDGITURL error message

fix(package): update travis-deploy-once for travis enterprise

Updating ensures that the README has correct instructions for Travis enterprise

fix(package): update travis-deploy-once

Makes sure Travis Enterprise is supported

feat: add support for Travis Enterprise

Pass on `travisUrl` as `travisOpts` to `travisDeployOnce`

Fixes #100

fix(package): update github to version 13.0.1

chore: Do not use itself

Update semantic-release and do not use itself to avoid incompatibilities

fix: Include lib in release

feat: add `githubToken`, `githubUrl` and `githubApiPathPrefix` options

`githubToken`, `githubUrl` and `githubApiPathPrefix` are not semantic-release options anymore. They now have to be set at the plugin level or via environment variables.

fix(package): update github to version 12.0.0