Standarized Makefile for go projects

[daviddias]

Ref: ipfs/community#276

Continue discussion here

[Stebalien]

What? This is not a community issue.

[daviddias]

@Stebalien exactly why I moved it to this repo for the DX working group :)

[Stebalien]

Oh! Sorry, I thought you were moving issues there and leaving these as tombstones.

[chriscool]

Copying make targets suggested in ipfs/community#276:

• make deps (installs gx and dependencies)
• make install (runs make build and installs resulting binary(ies))
• make check (runs go fmt and possibly go vet)
• make test (runs go test)
• make sharness (runs the sharness tests if available, otherwise exists with 0)
• make build (builds a binary if possible, otherwise exists with 0)