chore(package): update @angular-devkit/schematics to version 8.1.0

Closes #33

Author: greenkeeper[bot]

package.json

@@ -44,7 +44,7 @@
     "@angular/material": "^7.3.6"
   },
   "devDependencies": {
-    "@angular-devkit/schematics": "^7.3.7",
+    "@angular-devkit/schematics": "^8.1.0",
     "@angular/animations": "^7.2.11",
     "@angular/compiler": "^7.2.11",
     "@angular/compiler-cli": "^7.2.11",