These will be consumed by a gRPC service. The server has a public
interface that returns basic information, and a snapshotted list of peer
status/info.

Also some small drive-by fixes.

This change integrates the Bazel build system into bio-rd.

We also add support for:
  - running go dep from vendored libraries
  - running goveralls from vendored libraries
  - running bazel-based coverage from travis