Add check to make sure dopy is at least version 0.2.2 for digital_ocean module

cloud/digital_ocean

@@ -160,9 +160,14 @@ import os
 import time
 
 try:
+    import dopy
     from dopy.manager import DoError, DoManager
 except ImportError as e:
-    print "failed=True msg='dopy required for this module'"
+    print "failed=True msg='dopy >= 0.2.2 required for this module'"
+    sys.exit(1)
+
+if dopy.__version__ < '0.2.2':
+    print "failed=True msg='dopy >= 0.2.2 required for this module'"
     sys.exit(1)
 
 class TimeoutError(DoError):