fix(package): update @angular/pwa to version 0.901.0

Closes #31

Author: greenkeeper[bot]

demo/package.json

@@ -38,7 +38,7 @@
     "@angular/platform-browser": "7.2.5",
     "@angular/platform-browser-dynamic": "7.2.5",
     "@angular/platform-server": "7.2.5",
-    "@angular/pwa": "^0.13.7",
+    "@angular/pwa": "^0.901.0",
     "@angular/router": "7.2.5",
     "@angular/service-worker": "7.2.5",
     "@ng-bootstrap/ng-bootstrap": "^4.1.0",