Add release automation script (#399)

* v1.0.0-prerelease.8

* starting work on publish script

* add some silly logging

* more progress on publish script

* publish script in progress

* more work on pub script

* update draft of publish script

* add npm run publish script

* fix lerna version command line options

* trap ctrl-c in publish script

* add PR creation handling to publish script

* rephrase publish y/n

* don't print out git status during publish

* split publish task into publish and publishAsk

* activate the push and publishes for final testing

* remove remnants of first attempt at pub script

* use npm ci instead of install

* rename publish script to pub

* rename pub script to release

* rename pub script to 'release'

* reset package.json's (gitHead) after publish

* don't ask about publishing, lerna already does

* go to release branch before running `hub`

* add friendly logging to release script

* fix wording of hub-created PR

* fix clean working tree check in release script

* remove extraneous git status

* wrap then with parens

* remove parens

* co is not a git command :(

* removing whitespaces in cleanWorkspace

Author: mwcz

package-lock.json

@@ -18,6 +18,7 @@
     "clean": "rm -rf node_modules package-lock.json {elements,themes}/*/{node_modules,package-lock.json}",
     "bootstrap": "lerna bootstrap --hoist",
     "deploy-docs": "bash scripts/deploy-docs.sh",
+    "release": "bash scripts/release.sh",
     "postinstall": "npm run bootstrap && npm run build",
     "test-suite-inject": "node scripts/test-suite-inject.js",
     "doc-listing-inject": "node scripts/doc-listing-inject.js",