Remove custom nuget deploy script

This was a temporary workaround due to issues at AppVeyor.
Hopefully this was also the reason for deploy script to run
on non-master branches, since that branch is specified in the
deploy section.

Author: angularsen

appveyor.yml

@@ -39,6 +39,4 @@ deploy:
   skip_symbols: false
   on:
     branch: master
-deploy_script:
-  - appveyor DownloadFile https://dist.nuget.org/win-x86-commandline/latest/nuget.exe  
-  - ps: ($artifacts.values | Where-Object {($_.path -like '*.nupkg') -and  !($_.path -like '*.symbols.nupkg')}) | foreach-object {nuget.exe push $_.path -Source https://www.nuget.org/api/v2/package -ApiKey $env:api_key}
+