remove dependency on GOPATH

[hxrts]

On a relatively fresh ubuntu install, I download go for the first time per instructions, install github-cli, then clone scaffold.

When running make I get go-bindata: not found

I ultimately had to use the instructions here and execute the binary with an explicit install path to proceed with the sdk tutorial.

I realize this isn't exactly scaffold related, but as a non-go user just trying to play around with cosmos, this was a small hangup that may be helpful to make note of.

[tac0turtle]

It seems that GOPATH is needed for this tool. We should remove the dependency.