Update dependency rollup to v0.68.1

Author: renovate-bot

package.json

@@ -55,7 +55,7 @@
     "prettier": "1.13.7",
     "react": "16.4.1",
     "react-dom": "16.4.1",
-    "rollup": "0.60.7",
+    "rollup": "0.68.1",
     "rollup-plugin-babel": "3.0.7",
     "rollup-plugin-commonjs": "9.1.3",
     "rollup-plugin-node-globals": "1.2.1",

yarn.lock

@@ -7351,9 +7351,9 @@ rollup-pluginutils@^2.0.1:
     estree-walker "^0.3.0"
     micromatch "^2.3.11"
 
-rollup@0.60.7:
-  version "0.60.7"
-  resolved "https://registry.yarnpkg.com/rollup/-/rollup-0.60.7.tgz#2b62ef9306f719b1ab85a7814b3e6596ac51fae8"
+rollup@0.68.1:
+  version "0.68.1"
+  resolved "https://registry.yarnpkg.com/rollup/-/rollup-0.68.1.tgz#40d03872d3b05848fb023b12ebf7c6d69cab84c5"
   dependencies:
     "@types/estree" "0.0.39"
     "@types/node" "*"