add tsickle

Author: Georgi Peltekov

package.json

@@ -37,6 +37,7 @@
     "@angular/common": "^7.0.0",
     "@angular/platform-browser": "^7.0.0",
     "@angular/platform-browser-dynamic": "^7.0.0",
+    "tsickle": ">=0.27.3",
     "rxjs": "^6.3.3",
     "zone.js": "0.8.26"
   },