remove unused dependencies

package.json

@@ -69,7 +69,6 @@
     "babel-loader": "^7.1.4",
     "babel-plugin-transform-object-rest-spread": "^6.26.0",
     "babel-plugin-transform-runtime": "^6.15.0",
-    "babel-polyfill": "^6.26.0",
     "babel-preset-env": "^1.6.1",
     "chai": "^4.1.2",
     "codecov": "^3.0.0",
@@ -87,7 +86,6 @@
     "karma-chrome-launcher": "^2.2.0",
     "karma-coverage": "^1.1.1",
     "karma-mocha": "^1.3.0",
-    "karma-phantomjs-launcher": "^1.0.4",
     "karma-sinon-chai": "^1.3.4",
     "karma-spec-reporter": "^0.0.32",
     "karma-webpack": "3.0.0",