add react-test-render for snapshot testing

Author: jscottsmith

package.json

@@ -56,6 +56,7 @@
     "postcss-loader": "^1.3.3",
     "react": "^16.2.0",
     "react-dom": "^16.2.0",
+    "react-test-renderer": "^16.2.0",
     "regenerator-runtime": "^0.10.5",
     "sass-loader": "^6.0.3",
     "style-loader": "^0.16.1",