[KOGITO-3005] Add exe extension to Windows CLI

[Kevin-Mok]

See: https://issues.redhat.com/browse/KOGITO-3005

Test

I ran ./hack/go-build-cli.sh true 0.14.0 to produce kogito-cli-0.14.0-windows-amd64.zip (contains kogito.exe) which I uploaded here. Extracting it and running it works without asking which program to use it with:

PS C:\Users\Kevin> C:\Users\Kevin\Downloads\kogito.exe
{"level":"warn","T":"2020-08-07T17:08:47.685-0400","logger":"client_api","msg":"Kubernetes local configuration 'C:\\Users\\Kevin/.kube/config' is empty."}
{"level":"warn","T":"2020-08-07T17:08:47.686-0400","logger":"client_api","msg":"Make sure to login to your cluster with oc/kubectl before using this tool"}
panic: Impossible to get Kubernetes local configuration: invalid configuration: no configuration has been provided, try setting KUBERNETES_MASTER environment variable

goroutine 1 [running]:
github.com/kiegroup/kogito-cloud-operator/pkg/client.NewForConsole(0xc000539ee8)
        /home/kevin/go/src/github.com/kiegroup/kogito-cloud-operator/pkg/client/client.go:71 +0x9a
github.com/kiegroup/kogito-cloud-operator/cmd/kogito/command.DefaultBuildCommands(0xc000539f18)
        /home/kevin/go/src/github.com/kiegroup/kogito-cloud-operator/cmd/kogito/command/command.go:32 +0x29
main.Main(0xc000539f48, 0x4455ae)
        /home/kevin/go/src/github.com/kiegroup/kogito-cloud-operator/cmd/kogito/main.go:26 +0x29
main.Execute()
        /home/kevin/go/src/github.com/kiegroup/kogito-cloud-operator/cmd/kogito/main.go:32 +0x2d
main.main()
        /home/kevin/go/src/github.com/kiegroup/kogito-cloud-operator/cmd/kogito/main.go:39 +0x27

Note: The commit message has "Closes #500", so it'll close that issue automatically when this is merged.

Requirements

Many thanks for submiting your Pull Request ❤️!

Please make sure that your PR meets the following requirements:

• You have read the contributors' guide
• Pull Request title is properly formatted:
• Pull Request contains link to the JIRA issue
• Pull Request contains description of the issue
• Pull Request does not include fixes for issues other than the main ticket
• Your feature/bug fix has a unit test that verifies it
• You've tested the new feature/bug fix in an actual OpenShift cluster