Update appveyor config to NuGet publish on tag
Update appveyor config to NuGet publish on tag

- Add deploy config to publish nupkg to NuGet
- Add config to publish snupkg to NuGet

ericgreenmix/marten,mysticmind/marten,ericgreenmix/marten,mdissel/Marten,ericgreenmix/marten,mdissel/Marten,mysticmind/marten,JasperFx/Marten,JasperFx/Marten,mysticmind/marten,mysticmind/marten,JasperFx/Marten,ericgreenmix/marten