Implement go-import filter

The filter acts on http requests with go-get=1 as parameter.
This request is usually issued by go command [1]. The response
contains meta-data indicating the repo location on the server.
More discussion about the feature is available in RFC [2].

[1] https://golang.org/cmd/go/#hdr-Remote_import_paths
[2] https://gerrit-review.googlesource.com/#/c/98371/

Change-Id: I684f378d710bd8150bbd27dd589d1a796e12f920
10 files changed
tree: 4965a9a997958a38d564b35c54cda0254c81d6b5
  1. lib/
  2. src/
  3. .buckconfig
  4. .gitignore
  5. BUCK