Add imports for stdlib modules that are used.

This is cleanup that will aid us when we get ziploader implemented for 2.1

lib/ansible/module_utils/vca.py

@@ -14,6 +14,7 @@
 # You should have received a copy of the GNU General Public License
 # along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
 
+import os
 try:
     from pyvcloud.vcloudair import VCA
     HAS_PYVCLOUD = True