remove uglifyjs dependency; update ngx-bootstrap to 2.0-beta

package.json

@@ -16,7 +16,6 @@
     "test-e2e": "npm run e2e --prefix ./static"
   },
   "dependencies": {
-    "uglify-js": "^3.1.3"
   },
   "devDependencies": {
     "concurrently": "^3.4.0",

static/package.json

@@ -30,7 +30,7 @@
     "jquery": "^3.1.0",
     "jquery-ui": "^1.12.0",
     "jquery-ui-bundle": "^1.11.4",
-    "ngx-bootstrap": "^1.9.3",
+    "ngx-bootstrap": "^2.0.0-beta.6",
     "ngx-clipboard": "^8.1.0",
     "ngx-cookie-service": "^1.0.9",
     "rxjs": "^5.2.0",