Create a skeleton controller that does nothing

[bobcatfish]

It will be easier for ppl to start adding functionality if we add an empty controller that doesn't actually reconcile anything, just:

• Has all the config needed to build and deploy with ko
• Will start running and invoke a reconcile loop of some kind that does nothing (maybe just logs hello world?)

Additional info

Continuing to use knative/pkg is probably our best bet for now, in which case we can get a lot of this by more or less copying https://github.com/tektoncd/pipeline/blob/master/cmd/webhook.

[ncskier]

/assign @ncskier

[ncskier]

PR #18 completes this issue.