cli: Use go-homedir instead of os/user
cli: Use go-homedir instead of os/user

os/user requires cgo, preventing us from building static binaries.

Signed-off-by: Jonathan Rudenberg <3692bfa45759a67d83aedf0045f6cb635a966abf@titanous.com>

benbjohnson/flynn,benbjohnson/flynn,kgrz/flynn,GrimDerp/flynn,josephglanville/flynn,shads196770/flynn,rikur/flynn,ozum/flynn,arekkas/flynn,josephglanville/flynn,pkdevbox/flynn,TribeMedia/flynn,clifff/flynn,kgrz/flynn,jzila/flynn,tonicbupt/flynn,clifff/flynn,kgrz/flynn,schatt/flynn,pkdevbox/flynn,josephglanville/flynn,pkdevbox/flynn,jzila/flynn,supermario/flynn,felixrieseberg/flynn,josephglanville/flynn,benbjohnson/flynn,flynn/flynn,clifff/flynn,kgrz/flynn,lmars/flynn,flynn/flynn,rikur/flynn,supermario/flynn,kgrz/flynn,whouses/flynn,felixrieseberg/flynn,schatt/flynn,arekkas/flynn,clifff/flynn,shads196770/flynn,jzila/flynn,TribeMedia/flynn,shads196770/flynn,kgrz/flynn,justintung/flynn,shads196770/flynn,schatt/flynn,Brandywine2161/flynn,whouses/flynn,arekkas/flynn,lmars/flynn,flynn/flynn,tonicbupt/flynn,philiplb/flynn,GrimDerp/flynn,felixrieseberg/flynn,ozum/flynn,benbjohnson/flynn,philiplb/flynn,Brandywine2161/flynn,tonicbupt/flynn,benbjohnson/flynn,GrimDerp/flynn,justintung/flynn,justintung/flynn,schatt/flynn,jzila/flynn,flynn/flynn,supermario/flynn,jzila/flynn,TribeMedia/flynn,GrimDerp/flynn,Brandywine2161/flynn,justintung/flynn,Brandywine2161/flynn,pkdevbox/flynn,felixrieseberg/flynn,technosophos/flynn,philiplb/flynn,clifff/flynn,GrimDerp/flynn,lmars/flynn,Brandywine2161/flynn,flynn/flynn,clifff/flynn,lmars/flynn,whouses/flynn,arekkas/flynn,rikur/flynn,whouses/flynn,TribeMedia/flynn,Brandywine2161/flynn,technosophos/flynn,whouses/flynn,shads196770/flynn,supermario/flynn,schatt/flynn,philiplb/flynn,technosophos/flynn,arekkas/flynn,rikur/flynn,philiplb/flynn,tonicbupt/flynn,benbjohnson/flynn,justintung/flynn,jzila/flynn,whouses/flynn,pkdevbox/flynn,rikur/flynn,josephglanville/flynn,shads196770/flynn,lmars/flynn,pkdevbox/flynn,GrimDerp/flynn,ozum/flynn,schatt/flynn,tonicbupt/flynn,rikur/flynn,technosophos/flynn,ozum/flynn,TribeMedia/flynn,ozum/flynn,ozum/flynn,felixrieseberg/flynn,TribeMedia/flynn,josephglanville/flynn,technosophos/flynn,supermario/flynn,supermario/flynn,justintung/flynn