Append --v2-config-only to all v2 grpc configs

[davecheney]

When Envoy finds something invalid in the contour.yaml bootstrap config it falls back to parsing it as json which leads to confusing and hard to debug errors #136.

We can use --v2-config-only to force envoy to treat the file as yaml, and make the error easier to understand.

[cmaloney]

I'd be interested in trying to put together a simple patch to do this / get into contributing to contour

[davecheney]

Sure thing. Go for it, but I probably won't look at it til 0.3 is released on Thursday as we're grinding down to code complete now.

The trick is to remember to run the render.sh script in the deployment/ directory to regenerate the various rbac and non rbac versions of the manifests. Don't worry if you get it wrong, CI will catch it.