Build instructions in README.md are incorrect

[brianredbeard]

methinks that based on #2 showing that this endpoint has been having issues and the details therein that the information in README.md about installation is incorrect:

gssh/README.md

Lines 34 to 38 in 3f60308

	##### Installation
	1. Install go
	2. `go get -u -v github.com/square/gssh`

e.g.:

$ go get -u -v github.com/square/gssh
github.com/square/gssh (download)
github.com/square/erg (download)
github.com/square/grange (download)
github.com/deckarep/golang-set (download)
github.com/orcaman/concurrent-map (download)
unrecognized import path "vbom.ml/util/sortorder": reading https://vbom.ml/util/sortorder?go-get=1: 503 Service Unavailable
$ echo $?
1