Bump rollup from 1.32.1 to 2.0.1 (#2)

Author: dependabot-preview[bot]

package.json

@@ -15,7 +15,7 @@
   "devDependencies": {
     "react": "^16.9.0",
     "react-test-renderer": "^16.9.0",
-    "rollup": "^1.21.4",
+    "rollup": "^2.0.1",
     "rollup-plugin-buble": "^0.19.8",
     "tape": "^4.11.0"
   },