move even more code to cephlib
diff --git a/wally/utils.py b/wally/utils.py
index dfd0e8c..754734d 100644
--- a/wally/utils.py
+++ b/wally/utils.py
@@ -19,7 +19,7 @@
 logger = logging.getLogger("wally")
 
 
-STORAGE_ROLES = {'ceph-osd'}
+STORAGE_ROLES = ['ceph-osd']
 
 
 class StopTestError(RuntimeError):
@@ -121,9 +121,3 @@
     return exec_time_s, "{:%H:%M:%S}".format(end_dt)
 
 
-def shape2str(shape: Iterable[int]) -> str:
-    return "*".join(map(str, shape))
-
-
-def str2shape(shape: str) -> Tuple[int, ...]:
-    return tuple(map(int, shape.split('*')))