Added test_depend's on optional dependencies.

Author: Michael Koval

package.xml

@@ -33,4 +33,9 @@
   <run_depend>python-yaml</run_depend>
   <run_depend>python-lxml</run_depend>
   <test_depend>python-nose</test_depend>
+  <!-- These optional dependencies cause unit tests can fail if missing. -->
+  <test_depend>cbirrt2</test_depend>
+  <test_depend>or_cdchomp</test_depend>
+  <test_depend>or_ompl</test_depend>
+  <test_depend>or_parabolicsmoother</test_depend>
 </package>