Add first Cypress + React test

[davecalnan]

This PR:

• Removes the old Vue tests
• Adds a tests/cypress directory
• Adds test:e2e:run:react command to the root of the repo

This command uses start-server-and-test. This takes three arguments:

1. The setup command to build and start the dev server
2. The port/url it will wait until for it to return a 200
3. The test command to run

It's a handy way to build your package, start a server, run your tests and then close the server, all in one.