cmd/go: remove mentions of 'gotest' from the documentation go test runs the tests itself; it does not run the gotest command, so these mentions are confusing.
cmd/go: remove mentions of 'gotest' from the documentation
go test runs the tests itself; it does not run the gotest command,
so these mentions are confusing.

R=golang-dev, n13m3y3r
CC=golang-dev
http://codereview.appspot.com/5551043
abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go