Stem not checking for 'cached-microdescs.new' correctly
When "contoller.get_microdescriptors()" is called, it checks to see if the file "cached-microdescs" exists before creating a "stem.descriptor.reader.DescriptorReader" object. The problem is that "cached-microdescs" may not exist, but "cached-microdescs.new" does.
A simple fix for this is to modify stem/control.py:1795 (as of commit 73e5bd3e4f5) from:
elif not os.path.exists(cached_descriptor_path):
to:
elif not os.path.exists(cached_descriptor_path) and not os.path.exists(cached_descriptor_path+'.new'):