Update dependency rollup to v0.63.4 (#20)

Author: renovate[bot]

package-lock.json

@@ -36,7 +36,7 @@
     "lint-staged": "7.2.0",
     "prettier": "1.14.0",
     "rimraf": "2.6.2",
-    "rollup": "0.62.0",
+    "rollup": "0.63.4",
     "rollup-plugin-commonjs": "9.1.3",
     "rollup-plugin-node-builtins": "2.1.2",
     "tslint": "5.10.0",