ci: add e2e tests with cypress

* Creates E2E tests using Cypress and includes two tests

* Improves yarn.lock file

* Includes documentation

* Cypress project id

* test e2e w/ ci and video

* run unit command before e2e

* Also cache cypress

* Persist cypress to next build step

* Try a different path

* Try without working dir

* Persist less data, but restore yarn/cypress cache in next step

* Install cypress to invalidate cache

* Add e2e as a blocker for merged publishing

cypress/support/index.js

@@ -0,0 +1,20 @@
+// ***********************************************************
+// This example support/index.js is processed and
+// loaded automatically before your test files.
+//
+// This is a great place to put global configuration and
+// behavior that modifies Cypress.
+//
+// You can change the location of this file or turn off
+// automatically serving support files with the
+// 'supportFile' configuration option.
+//
+// You can read more here:
+// https://on.cypress.io/configuration
+// ***********************************************************
+
+// Import commands.js using ES2015 syntax:
+import './commands';
+
+// Alternatively you can use CommonJS syntax:
+// require('./commands')