Thanks for the tips! You saved me lots of time, so here you have a Dockerfile based on your post:
```
#
# dropahead steempy container
#
# VERSION               0.0.1
#

FROM python:3

# Update packages
RUN apt-get update
RUN apt-get upgrade -y

# Install steempy
RUN pip install -U steem

# Patch steempy metadata
RUN sed -i 's/0.9.3.1/0.9.3/' /usr/local/lib/python3.6/site-packages/steem-0.18.103.dist-info/METADATA

# Start supervisor
CMD ["/bin/sh"]
```