chore(deps): update dependency rollup-plugin-typescript2 to v0.21.1

Author: renovate-bot

package-lock.json

@@ -109,7 +109,7 @@
     "rollup-plugin-node-resolve": "4.2.4",
     "rollup-plugin-preserve-shebang": "0.1.6",
     "rollup-plugin-sourcemaps": "0.4.2",
-    "rollup-plugin-typescript2": "0.21.0",
+    "rollup-plugin-typescript2": "0.21.1",
     "semantic-release": "15.13.3",
     "travis-deploy-once": "5.0.11",
     "ts-jest": "24.0.0",