When we received an error message from the Review Board API, if we

didn't have a pre-generated string for that error code locally we would

include the error body verbatim. We did this by attempting to cast it to

a string and encode it to utf-8, but that only works on Python 2 where

str is actually bytes. On Python 3, an error is raised becuase you are

not allowed to decode a bytes object into text without a codec.
Instead, we now return text from the API errors when calling str(e) on

them, instead of returning their body verbatim.
While I was here, I also removed a bunch of unnecessary unicode

literals. We are using unicode_literals everywhere so they were

redundant.

Confirmed the on Python versions 2.7, 3.5, 3.6, and 3.7:

With this entire patch stack (/r/10685, /r/10695, and /r/10696),

rbt post is able to create review requests with commit history.