在Windows上安装swaggo(swagger +杜松子酒)

I am trying to setup swagger for gin-gonic on windows. Documentation of swaggo states that I should run:

go get -u github.com/swaggo/swag/cmd/swag

After installation I should be able to run swag init from within the root of my project where I have main.go, but the cmdlet states the following:

swag : The term 'swag' is not recognized as the name of a cmdlet, function, script file, or operable program. Check
the spelling of the name, or if a path was included, verify that the path is    correct and try again.
At line:1 char:1
+ swag
+ ~~~~
+ CategoryInfo          : ObjectNotFound: (swag:String) [],  CommandNotFoundException
+ FullyQualifiedErrorId : CommandNotFoundException

How can I add swag to PATH or how should I proceed from here?

Ps, i followed documentation from here

Update: So I did a clean installation of Go on another PC, followed by go get -u github.com/swaggo/swag/cmd/swag and swag runs right of the bat. Earlier I followed this tutorial and I might have accidentally messed up my $GOPATH on the original PC.

add $GOPATH/bin to PATH, for example:

export PATH=$PATH:/Users/.../go/bin