Cleanup Godeps

`godep save` and `godep update` don't copy `*_test.go` files and
`testdata` directories by default, and we have no reason to keep
them in Godeps.

This is what I did:
1. A clean GOPATH with no vendors in
2. godep restore
3. remove Godeps dir in the repo
4. godep save

Note that I'm using the latest godep, so we also vendored all
necessary licese files because of https://github.com/tools/godep/pul/301

Signed-off-by: Qiang Huang <[email protected]>

Author: hqhq