Add a POWDER note about why screenshots have cloudlab name/logo.

7 jobs for generalize-openstack-tutorial in 2 minutes and 2 seconds (queued for 1 second)
Status Job ID Name Coverage
  Build
passed #2439
apt

00:00:50

passed #2440
cloudlab

00:01:37

passed #2441
emulab

00:00:54

passed #2442
phantomnet

00:00:38

passed #2443
powder

00:00:52

 
  Deploy
passed #2444
pages

00:00:25

passed pages:deploy

00:00:01