Windows asset

[migounette]

Add windows binary in .go-releaser, in order to get an existing asset
Ad it works with Docker Desktop

PS C:\temp\kubectl-whoami> go build -o kubectl-whoami.exe .\main.go
go: downloading k8s.io/cli-runtime v0.17.0
go: downloading k8s.io/client-go v0.17.0
go: downloading k8s.io/api v0.17.0
go: downloading k8s.io/apimachinery v0.17.0
go: downloading github.com/evanphx/json-patch v4.2.0+incompatible
go: downloading sigs.k8s.io/yaml v1.1.0
go: downloading golang.org/x/text v0.3.2
go: downloading github.com/gogo/protobuf v1.2.2-0.20190723190241-65acae22fc9d
go: downloading golang.org/x/crypto v0.0.0-20190820162420-60c769a6c586
go: downloading github.com/googleapis/gnostic v0.0.0-20170729233727-0c5108395e2d
go: downloading golang.org/x/net v0.0.0-20191004110552-13f9640d40b9
go: downloading github.com/google/gofuzz v1.0.0
go: downloading gopkg.in/yaml.v2 v2.2.4
go: downloading golang.org/x/time v0.0.0-20190308202827-9d24e82272b4
go: downloading k8s.io/utils v0.0.0-20191114184206-e782cd3c129f
go: downloading github.com/Azure/go-autorest/autorest/adal v0.5.0
go: downloading github.com/gophercloud/gophercloud v0.1.0
go: downloading golang.org/x/sys v0.0.0-20190826190057-c7b8b68b1456
go: downloading github.com/pkg/errors v0.8.1
go: downloading github.com/Azure/go-autorest/autorest/date v0.1.0
go: downloading cloud.google.com/go v0.38.0
go: downloading k8s.io/kube-openapi v0.0.0-20191107075043-30be4d16710a
PS C:\temp\kubectl-whoami> .\kubectl-whoami.exe
docker-for-desktop