Proof-of-concept tests with jest & puppeteer

[hstove]

Jest is a very popular JS framework for running any kind of tests.

Puppeteer is becoming the go-to framework for running integration tests in a headless browser, which is faster than Selenium, and requires less of an overhead.

jest-puppeteer is a great plugin that makes it easy to write test expectations using puppeteer.

This PR is really a proof-of-concept way for me to write some extra integration tests, while trying to fix issues related to our protractor/selenium based tests.