Merge pull request #84 from milahu/add-dep-tslib

add dep tslib

Author: jridgewell

package-lock.json

@@ -52,6 +52,7 @@
     "rollup-plugin-sourcemaps": "0.6.2",
     "source-map": "0.6.1",
     "ts-jest": "26.1.0",
+    "tslib": "2.0.1",
     "tslint": "6.1.2",
     "tslint-config-prettier": "1.18.0",
     "tslint-config-standard": "9.0.0",