Proto commits in uber/aresdb

These 4 commits are when the Protocol Buffers files have changed:

Commit:f46f9db
Author:Jian Shen
Committer:GitHub

BorrowConnection from multiple peers and pick the first healthy peer (#257) * BorrowConnection from multiple peer and pick the first healthy connection * address comments * shuffle peer hosts and add more logging * add source and startedAt to ui

The documentation is generated from this commit.

Commit:06d2db9
Author:voyager-dw
Committer:GitHub

bootstrap logic in server side (#199) * bootstrap logic in server side * update lint * add grpc file transfer benchmark and tests * add acquire bootstrap usage * add acquire/release token * fix mock * add more tests * address comment

Commit:4545f91
Author:Jian Shen
Committer:GitHub

peer data streaming grpc (#188) * add grpc peer streaming protocol * data node peer streaming protocol * address comments

Commit:6d9261d
Author:Jian Shen
Committer:GitHub

open source controller code (mutators, tasks) (#179) * controller * add mutators and tasks from controller to aresdb * add tests * missing liscense header * address comments; add tests * address comments * modify gitignore