Fix ec2_setup task param quoting

test/integration/roles/setup_ec2/tasks/main.yml

@@ -17,7 +17,7 @@
 # along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
 
 - name: generate random string
-  shell: python -c "import string,random; print ''.join(random.choice(string.ascii_lowercase) for _ in xrange(8));"
+  command: python -c \"import string,random; print ''.join(random.choice(string.ascii_lowercase) for _ in xrange(8));\"
   register: random_string
   tags:
     - prepare