Refactored Watcher codebase to add py34 support

Even though Watcher was mentioning python 3.4 as supported, it
really wasn't the case as all the unit tests were not passing in this
version of Python.

This patchset fixes all the failing tests in Python 3.4 while
keeping Watcher Python 2.7 compatible.

DocImpact
BugImpact
Change-Id: Ie74acc08ef0a2899349a4b419728c89e416a18cb

watcher/api/controllers/v1/utils.py

@@ -28,10 +28,18 @@ JSONPATCH_EXCEPTIONS = (jsonpatch.JsonPatchException,
 
 
 def validate_limit(limit):
-    if limit is not None and limit <= 0:
+    if limit is None:
+        return CONF.api.max_limit
+
+    if limit <= 0:
+        # Case where we don't a valid limit value
         raise wsme.exc.ClientSideError(_("Limit must be positive"))
 
-    return min(CONF.api.max_limit, limit) or CONF.api.max_limit
+    if limit and not CONF.api.max_limit:
+        # Case where we don't have an upper limit
+        return limit
+
+    return min(CONF.api.max_limit, limit)
 
 
 def validate_sort_dir(sort_dir):