Cant get package without mercurial

Created by: terbooter

root@vagrant-ubuntu-trusty-64:/vagrant/go# go get github.com/gonum/plot
go: missing Mercurial command. See https://golang.org/s/gogetcmd
package bitbucket.org/zombiezen/gopdf/pdf: exec: "hg": executable file not found in $PATH

It requires mercurial