Update test dependencies (#572)

* move Cypress to the optionalDependencies section

* remove protractor

* remove dead protractor test files

frontend/package.json

@@ -93,7 +93,6 @@
     "@types/node": "^12.11.1",
     "codelyzer": "^6.0.1",
     "concurrently": "^6.2.0",
-    "cypress": "7.4.0",
     "cypress-wait-until": "^1.7.1",
     "http-proxy-middleware": "^1.0.5",
     "jasmine-core": "~3.6.0",
@@ -103,9 +102,11 @@
     "karma-coverage": "~2.0.3",
     "karma-jasmine": "~4.0.0",
     "karma-jasmine-html-reporter": "^1.5.0",
-    "protractor": "~7.0.0",
     "ts-node": "~8.3.0",
     "tslint": "~6.1.0",
     "typescript": "~4.1.5"
+  },
+  "optionalDependencies": {
+    "cypress": "^7.4.0"
   }
 }