adding gh-pages branch to ignore for appveyor

Author: Almenon

appveyor.yml

@@ -1,5 +1,9 @@
 # this script based off of https://github.com/tolbertam/mocha-appveyor-reporter/blob/master/appveyor.yml
 
+branches:
+  except:
+    - gh-pages
+
 image:
 - Visual Studio 2017
 - Ubuntu