Add @grafana/e2e

Author: amotl

package.json

@@ -18,6 +18,7 @@
   "author": "Grafana Labs",
   "license": "MIT",
   "devDependencies": {
+    "@grafana/e2e": "^7.3.1",
     "@grafana/toolkit": "^7.3.1",
     "@types/grafana": "https://[email protected]/CorpGlory/types-grafana.git",
     "@types/lodash": "^4.14.118",