Move common storage, plot and statistic code to cephlib
diff --git a/wally/ceph.py b/wally/ceph.py
index 3527db3..89324c5 100644
--- a/wally/ceph.py
+++ b/wally/ceph.py
@@ -144,7 +144,7 @@
     return path
 
 
-class FillCephInfoStage(Stage):
+class CollectCephInfoStage(Stage):
     config_block = 'ceph'
     priority = StepOrder.UPDATE_NODES_INFO