Remove deps

Remove the dependency.

The most important would be the glog removal. It declares tons of flags so it pollutes the `-help` when we import `gobrake`. It also uses `-v` so any `gobrake` caller can't declare its own `-v`.

I also removed the `go-httpclient` because it seemed a bit overkill to import a full package for couple of lines.

It also have the advantage to make `gobrake` "standalone" and not pollute the `Godeps` of callers.

I would also remove `gomega` and `ginkgo` to be 100% standalone. But didn't want to push too much, and `Godeps` does not embed them for caller packages.