move get_distribution_version() to basic.py

lib/ansible/module_utils/basic.py

@@ -142,6 +142,18 @@ def get_distribution():
         distribution = None
     return distribution
 
+def get_distribution_version():
+    ''' return the distribution version '''
+    if platform.system() == 'Linux':
+        try:
+            distribution_version = platform.linux_distribution()[1]
+        except:
+            # FIXME: MethodMissing, I assume?
+            distribution_version = platform.dist()[1]
+    else:
+        distribution_version = None
+    return distribution_version
+
 def load_platform_subclass(cls, *args, **kwargs):
     '''
     used by modules like User to have different implementations based on detected platform.  See User