Add "use" as an alias for "set"

[jsumners]

I find myself trying to g use <version> every time I come back to this tool only to get an error. So I am suggeting this alias.

I have skipped adding documentation for this alias because I'm not sure what that should look like.
The n tool has aliases and documents them in a
separate list from the non-aliased commands. But
no prior aliases exist here.

[ankitcharolia]

@jsumners @stefanmaric kindly try this GO Version Manager: https://github.com/ankitcharolia/goenv

[jsumners]

I understand you want people to use your tool, but spamming other tools's pull requests is not the way to gain users. It really just turns people off it completely.