Git HTTP: POST /{upload,receive}-pack Client Implementation

Depends on Migration Analysis #92 (closed)

Depends on RPC Design gitaly-proto!4 (merged)

Depends on Server Implementation #122 (closed)

~"Client Implementation" Git HTTP: POST /{upload,receive}-pack

Goal: allow Gitaly to monitor and control the git upload-pack and git receive-pack server-side processes spawned by the Git 'smart HTTP' transport. Note that the GET requests of this transport can already be forwarded.

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information