sim: Add statvfs and mkdir stubs

sim/run.py

@@ -107,6 +107,8 @@ def _mkmock(fun):
 
 os.listdir = _mkmock(os.listdir)
 os.stat = _mkmock(os.stat)
+os.statvfs = _mkmock(os.statvfs)
+os.mkdir = _mkmock(os.mkdir)
 builtins.open = _mkmock(builtins.open)
 
 orig_stat = os.stat