[quickstart] Support non-rbac clusters

[chuckha]

Right now we only have an RBAC solution for the quickstart. We would like to support clusters that do not have RBAC.

Work involved: If #52 gets merged, then we can add an if statement in the ksonnet that doesn't generate the rbac objects if a particular flag is passed in. Then in the makefile we can add an environment variable to the generate-examples target. Since the only dependency is docker for building the quickstart examples, we can then encourage non-rbac users to regenerate the examples with a particular flag or we could maintain a generated copy of that JSON.

[timothysc]

This is where the ksonnet/kcfg init comes in to auto-detect caps and cache vars used for generation.

/cc @hausdorff

[hausdorff]

Not sure how I missed this, but we're actually pretty close to supporting this.

[jesscodez]

Done with #58