adjust our code to call processes to act like `tee`

We should be capturing error text for rerendering calls in subprocesses. It is nice to see them in the bot logs too. Thus we should `tee` the output.

see
- https://stackoverflow.com/questions/2996887/how-to-replicate-tee-behavior-in-python-when-using-subprocess
- https://github.com/python/cpython/blob/master/Lib/subprocess.py#L509
- https://docs.python.org/3/library/subprocess.html