Changes .gitignore to ignore nuget packages.
Changes .gitignore to ignore nuget packages.

cloudfoundry-incubator/garden-windows,stefanschneider/garden-windows,cloudfoundry-incubator/garden-windows,cloudfoundry/garden-windows,cloudfoundry/garden-windows,cloudfoundry/garden-windows,stefanschneider/garden-windows,stefanschneider/garden-windows,cloudfoundry-incubator/garden-windows