fixed minor bug where minute was being used as month for the default create timestamp when creating a stack

Author: trautmane

renderapi/stack.py

@@ -50,7 +50,7 @@ def __init__(self, cycleNumber=None, cycleStepNumber=None,
         self.stackResolutionZ = stackResolutionZ
         self.mipmapPathBuilder = mipmapPathBuilder
         self.materializedBoxRootPath = materializedBoxRootPath
-        self.createTimestamp = (strftime('%Y-%M-%dT%H:%M:%S.00Z') if
+        self.createTimestamp = (strftime('%Y-%m-%dT%H:%M:%S.00Z') if
                                 createTimestamp is None else createTimestamp)
         self.versionNotes = versionNotes