Project-specific configs

[mishnea]

gov can read a config file in the CWD to set the Go version. Perhaps it could be activated the same way as in NVM, i.e. gov use with no arguments.
Preferably, however, the Go version is "changed" automatically. I guess it could use a shell script for go, rather than the actual binary, which uses the CWD to determine the correct version of Go to run