implement script to tag releases

[0xadada]

Goal

Easily create tagged release with a release branch off master.

Expected Behavior

When a release has been tested, QA'ed and ready for launch:

ember release <ARGUMENTS>

• tags master with release number
• creates release branch
• pushes both to github

Considerations

• https://github.com/lytics/ember-cli-release#readme
• https://github.com/skywinder/github-changelog-generator
• https://github.com/runspired/ember-cli-changelog#readme
• examples: https://github.com/offirgolan/ember-cp-validations/blob/master/config/changelog.js

# Generate release notes from last MINOR release tag, crediting each author per commit.
git log `git describe --abbrev=0 --tags`.. --pretty=format:"* %s - @%an"

# Generate release notes from last MINOR release tag, rollup commits to each author
git shortlog `git describe --abbrev=0 --tags`..

Creation of git tags, see https://github.com/0xadada/dockdj/blob/master/bin/deploy#L86

Tasks

List all of the subtasks that will contribute to completion of this issue. Once
all subtasks are complete, that will indicate the issue is "done".

• Create bash script
• Test on a test repo w/o pushing