streams: disable bodhi-updates and next-devel for now

There's more work needed before we can unblock those. For background,
on bodhi-updates, see:

coreos/fedora-coreos-config#335 (comment)

For the next-devel stream, see:

coreos/fedora-coreos-tracker#283 (comment)

streams.groovy

@@ -1,8 +1,8 @@
 // Canonical definition of all our streams and their type.
 
 production = ['testing', 'stable' /* , 'next' */]
-development = ['testing-devel', 'next-devel']
-mechanical = ['bodhi-updates' /* , 'bodhi-updates-testing', 'branched', 'rawhide' */]
+development = ['testing-devel' /* , 'next-devel' */]
+mechanical = [/*'bodhi-updates', 'bodhi-updates-testing', 'branched', 'rawhide' */]
 
 // Maps a list of streams to a list of GitSCM branches.
 def as_branches(streams) {