Delete security group after terminating instance.

This patch slightly modifies the order of operations in the euca exercise
script.  It moves the deletion of the security group to the end, after
the instance has been terminated.  The reason this change must be made
is because of this change proposed to nova:

    https://review.openstack.org/#change,4154

Without this change, when exercise.sh is run against this patch, the euca
exercises will fail when the security group is deleted.  Moving it to the
end should make it pass, as the security group will no longer be in use.

Change-Id: I9095a02c42173ed1837ec20b38d5ef00fe4474ec
diff --git a/AUTHORS b/AUTHORS
index b147827..5769f4f 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -16,6 +16,7 @@
 Johannes Erdfelt <johannes.erdfelt@rackspace.com>
 Justin Shepherd <galstrom21@gmail.com>
 Kiall Mac Innes <kiall@managedit.ie>
+Russell Bryant <rbryant@redhat.com>
 Scott Moser <smoser@ubuntu.com>
 Todd Willey <xtoddx@gmail.com>
 Tres Henry <tres@treshenry.net>
diff --git a/exercises/euca.sh b/exercises/euca.sh
index 834e4ec..7f48695 100755
--- a/exercises/euca.sh
+++ b/exercises/euca.sh
@@ -74,9 +74,6 @@
 # Revoke pinging
 euca-revoke -P icmp -s 0.0.0.0/0 -t -1:-1 $SECGROUP
 
-# Delete group
-euca-delete-group $SECGROUP
-
 # Release floating address
 euca-disassociate-address $FLOATING_IP
 
@@ -97,3 +94,6 @@
 
 # Terminate instance
 euca-terminate-instances $INSTANCE
+
+# Delete group
+euca-delete-group $SECGROUP