Add a Go SDK

[lukehoban]

This is 99% the work of @lblackstone and @pgavlin 🙏 .

It is still WIP, but opening the PR as it is now in a usable state and ready for more eyes.

package main

import (
	corev1 "github.com/pulumi/pulumi-kubernetes/sdk/go/kubernetes/core/v1"
	"github.com/pulumi/pulumi/sdk/go/pulumi"
)

func main() {
	pulumi.Run(func(ctx *pulumi.Context) error {
		_, err := corev1.NewPod(ctx, "foo", &corev1.PodArgs{
			Spec: corev1.PodSpecArgs{
				Containers: corev1.ContainerArray{
					corev1.ContainerArgs{
						Name:  pulumi.String("nginx"),
						Image: pulumi.String("nginx"),
					},
				},
			},
		})
		if err != nil {
			return err
		}

		return nil
	})
}

Fixes #70.

[lukehoban]

Looks like I'm not allowed to "Approve" since I opened this - but LGTM 🎉. @lblackstone you may need to sign off yourself to unblock the review checks.

[lblackstone]

Ok, just need to merge #1021 and then resolve merge conflicts with this PR and we should be good to go.