adds the steps to automatically publish the protobuf direct client use

[andrewxhill]

• the current client uses an embedded protoc step
• this should allow to just swap in the lib generated here with all the client side types

this could actually just be wrong, all these might be available directly in the Mobile package, but it didn't seem clear if they were. either way I wanted to figure out the required steps since I need it to build java client lib out of go-threads.

todo

• test the output in the client lib
• configure the job to actually publish the output to bintray
• reconfigure the job to only run on release not on a branch.