fix(package): update @angular/material to version 9.1.3

Closes #34

Author: greenkeeper[bot]

demo/package.json

@@ -34,7 +34,7 @@
     "@angular/flex-layout": "^7.0.0-beta.24",
     "@angular/forms": "7.2.5",
     "@angular/http": "7.2.5",
-    "@angular/material": "^7.3.6",
+    "@angular/material": "^9.1.3",
     "@angular/platform-browser": "7.2.5",
     "@angular/platform-browser-dynamic": "7.2.5",
     "@angular/platform-server": "7.2.5",