Migrating from govendor to go dep

Change-Id: I08f2863450e141f1fed0bdef4b9ba64157c7289d
diff --git a/vendor/golang.org/x/crypto/CONTRIBUTORS b/vendor/golang.org/x/crypto/CONTRIBUTORS
new file mode 100644
index 0000000..1fbd3e9
--- /dev/null
+++ b/vendor/golang.org/x/crypto/CONTRIBUTORS
@@ -0,0 +1,3 @@
+# This source code was written by the Go contributors.
+# The master list of contributors is in the main Go distribution,
+# visible at https://tip.golang.org/CONTRIBUTORS.