Merge pull request #869 from owncloud/add_tslib_library

Add the tslib dependency required for prettier-eslint 16.4.1

Author: mmattel

package-lock.json

@@ -87,6 +87,7 @@
     "require-from-string": "^2.0.1",
     "standard": "^17.1.2",
     "stylelint-config-standard": "^34.0.0",
+    "tslib": "^2.8.1",
     "typeface-open-sans": "^1.1.13",
     "typeface-roboto-mono": "^1.1.13",
     "vinyl-buffer": "^1.0.0"