Missing dependencies in install instructions

[GUI]

When following the setup instructions for installing the web server, I ran into errors related to missing dependencies. Here's an example of the errors on a completely fresh install (go version 1.3.3):

$ export GOPATH=/tmp/freegeoip
$ go get github.com/fiorix/freegeoip
$ go install github.com/fiorix/freegeoip/cmd/freegeoip
/tmp/freegeoip/src/github.com/fiorix/freegeoip/cmd/freegeoip/main.go:20:2: cannot find package "github.com/fiorix/go-redis/redis" in any of:
    /opt/local/go/src/pkg/github.com/fiorix/go-redis/redis (from $GOROOT)
    /tmp/freegeoip/src/github.com/fiorix/go-redis/redis (from $GOPATH)
/tmp/freegeoip/src/github.com/fiorix/freegeoip/cmd/freegeoip/main.go:21:2: cannot find package "github.com/gorilla/context" in any of:
    /opt/local/go/src/pkg/github.com/gorilla/context (from $GOROOT)
    /tmp/freegeoip/src/github.com/gorilla/context (from $GOPATH)

I was able to fix this by explicitly getting the go-redis and context packages before running the install command. This pull request simply updates the readme with these additional commands to get those packages.

However, I'm new to Go, so if there's a way to setup those packages as dependencies so they automatically get fetched, that might be preferable, but I at least wanted to raise the issue for anyone else that might be running into this on a fresh install.

Thanks for the great package!

[fiorix]

I think if you just do go get github.com/fiorix/freegeoip/cmd/freegeoip it should download all dependencies and build the binary already. Could you please check? That'd be a much simpler change in the instructions: from go install to go get.

[GUI]

Ah, that simpler approach worked great. Thanks! I've updated this PR if you want 2 commits to change one word. :)

[fiorix]

That's fine. Thank you!