chore(package): update rollup to version 1.3.1

Closes #13

Author: greenkeeper[bot]

package.json

@@ -89,7 +89,7 @@
     "react-router-dom": "^4.3.1",
     "react-scripts": "1.1.4",
     "react-test-renderer": "^16.6.0",
-    "rollup": "^0.67.4",
+    "rollup": "^1.3.1",
     "rollup-plugin-babel": "^4.0.3",
     "rollup-plugin-commonjs": "^9.1.3",
     "rollup-plugin-node-resolve": "^3.3.0",