Add nuget packages to appveyor cache

Author: Kapil Borle

appveyor.yml

@@ -4,6 +4,10 @@ os:
 # clone directory
 clone_folder: c:\projects\psscriptanalyzer
 
+# cache nuget packages
+cache:
+    - '%USERPROFILE%\.nuget\packages -> **\project.json'
+
 # Install Pester
 install:
     - cinst -y pester --version 3.4.0