Remove file RELEASE-NOTES
Remove file RELEASE-NOTES

The symbolic link that RELEASE-NOTES pointed to no longer exists.
Many other projects don't have a RELEASE-NOTES file, so let's just
delete it.

Change-Id: I7fa24759630e76952f3742de01a58e4fc4eb2465

pshchelo/ironic,openstack/ironic,openstack/ironic,pshchelo/ironic