fix(dev): don't buffer Django output

[krishnans2006]

Proposed changes

• Set the PYTHONUNBUFFERED environment variable in entrypoint.sh

Brief description of rationale

Previously, print statements without flush=True would not be displayed until a server restart. This change unbuffers stdout and stderr from Django's development server to allow for easier debugging with print statements.

[coveralls]

coverage: 79.792%. remained the same
when pulling 7f801a9 on krishnans2006:dev-fixes
into 1657c3b on tjcsl:dev.