chore: remove 3 unused packages from package.json

In response to https://github.com/angular/quickstart/commit/ea70d3a88dae6d3c104bb60fe343caf037e1bb76#commitcomment-19166659

package.json

@@ -58,9 +58,6 @@
     "karma-htmlfile-reporter": "^0.3.4",
     "karma-jasmine": "^1.0.2",
     "karma-jasmine-html-reporter": "^0.2.2",
-    "karma-phantomjs-launcher": "^1.0.2",
-    "karma-sourcemap-loader": "^0.3.7",
-    "karma-webpack": "^1.8.0",
     "protractor": "^3.3.0",
     "rimraf": "^2.5.2"
   },