Adding missing package for fixing build error.

Author: renemadsen

eform-client/package.json

@@ -29,6 +29,7 @@
     "@ngx-gallery/lightbox": "^3.1.0",
     "@ngx-translate/core": "^10.0.2",
     "@ngx-translate/http-loader": "^3.0.1",
+    "@types/dragula": "2.1.33",
     "angular-calendar": "^0.26.0",
     "angular2-uuid": "^1.1.1",
     "chart.js": "^2.5.0",