`gvm use` and `gvm install` migration

[devhindo]

I suggest a command to be just gvm use and it will detect the go.mod file > download the version there if not available using go install and if no minor version is specified we can just choose the latest available one, then it gvm use that version.

current behavior :

gvm install also should detect the version from the current directory go.mod file and downloads the version from there