Allow e2e tests to run with vagrant

The function detect-project is meaningless and vague outside of GCE, so please do not add it to the Vagrant setup.  

The function detect-project is called in the GCE bash scripts by the kube-up() and kube-push() functions, can we just invoke kube-up() instead?

If not, can we add a new function that more accurately describes the need?

For example, can we have the following:

```
// Perform and preparations required to run e2e tests
function prepare-e2e() {
}
```

The GCE implementation of that function could call detect-project(), and the Vagrant environment can do what it pleases as well.