How do I install requirements in Go? "cannot find package"

I'm new to Go and I'm trying to set up a Go project with minimal documentation: https://github.com/alphagov/metadata-api

I've cloned it, but when I try go build I get the following warnings:

main.go:8:2: cannot find package "github.com/Sirupsen/logrus" in any of:
    /usr/local/Cellar/go/1.3.3/libexec/src/pkg/github.com/Sirupsen/logrus (from $GOROOT)
    /Users/me/go/src/github.com/Sirupsen/logrus (from $GOPATH)
main.go:14:2: cannot find package "github.com/alphagov/metadata-api/content_api" in any of:
    /usr/local/Cellar/go/1.3.3/libexec/src/pkg/github.com/alphagov/metadata-api/content_api (from $GOROOT)
    /Users/me/go/src/github.com/alphagov/metadata-api/content_api (from $GOPATH)

I'm guessing this is because I haven't installed the Go equivalent of requirements?

My GOPATH is set:

metadata-api$ echo $GOPATH
/Users/me/go

And the Go executable is in

metadata-ape$ echo $PATH
....:/Users/me/go/bin

What do I need to do to help Go find these packages?

You should install package first:

try

$ go get github.com/Sirupsen/logrus

and check you $GOPATH dir

This project use gom as the package manager,

Make sure you have installed gom

or try this command

$ gom install

I think your $GOPATH and $PATH settings are incorrect, the $GOPATH environment variable specifies the location of your workspace, these are my path settings:

export GOROOT=$HOME/bin/go
export GOBIN=$GOROOT/bin
export GOPATH=$HOME/golang
export PATH=$PATH:$GOBIN

Stack Overflow Q#27249420, score: 102