Revert "ginkgo: install on demand via go get -u"

This reverts commit de05e5816869073600ae8e851093b4b9a9d7fab0.

Running `go get -u` will change the local Go module causing CI to fail
as the local git tree is being changed.  Reverting the change for now
until we have a better idea.

Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

vendor/github.com/nxadm/tail/tail.go

@@ -435,7 +435,6 @@ func (tail *Tail) sendLine(line string) bool {
 // Cleanup removes inotify watches added by the tail package. This function is
 // meant to be invoked from a process's exit handler. Linux kernel may not
 // automatically remove inotify watches after the process exits.
-// If you plan to re-read a file, don't call Cleanup in between.
 func (tail *Tail) Cleanup() {
 	watch.Cleanup(tail.Filename)
 }