fix(package): update @angular/cdk to version 8.1.1

Closes #34

Author: greenkeeper[bot]

package.json

@@ -36,7 +36,7 @@
     "check-travis": " travis-status --repo=angular-material-extensions/faq --branch=master --fail-pending || echo 'Not yet passing'"
   },
   "dependencies": {
-    "@angular/cdk": "^7.3.6",
+    "@angular/cdk": "^8.1.1",
     "@angular/common": "^7.2.11",
     "@angular/core": "^7.2.11",
     "@angular/flex-layout": "^7.0.0-beta.24",