chore(package): update rollup to version 2.2.0 (#307)

Closes #305

Co-authored-by: greenkeeper[bot] <23040076+greenkeeper[bot]@users.noreply.github.com>

package.json

@@ -61,7 +61,7 @@
     "gulp-sass": "^4.0.0",
     "gulp-shell": "^0.8.0",
     "jest": "^25.1.0",
-    "rollup": "^1.14.5",
+    "rollup": "^2.2.0",
     "rollup-plugin-babel": "^4.0.3",
     "rollup-plugin-commonjs": "^10.0.0",
     "rollup-plugin-node-resolve": "^5.0.0",