chore(package): update rollup-plugin-commonjs to version 9.1.3

Closes #33

Author: greenkeeper[bot]

package.json

@@ -29,7 +29,7 @@
     "jest-cli": "21.2.1",
     "rollup": "^0.53.0",
     "rollup-plugin-babel": "^3.0.2",
-    "rollup-plugin-commonjs": "8.2.6",
+    "rollup-plugin-commonjs": "9.1.3",
     "rollup-plugin-node-resolve": "3.0.0",
     "rollup-plugin-sourcemaps": "^0.4.1",
     "rollup-plugin-uglify": "^2.0.1",