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>

dependencies/dependencies.go

@@ -0,0 +1,5 @@
+package dependencies
+
+import (
+	_ "github.com/onsi/ginkgo/ginkgo"
+)