build(docs): pin Python dependencies

Recently some of our dependencies' dependencies have come into conflict
and are now causing errors when trying to install the Python
requirements. This change introduces `` - a list of our
own direct dependencies, and pins them to specific versions.

The existing `requirements.txt` file is now automatically generated by
the `pip-compile` tool - part of the pip-tools package - and ensures
that our dependency tree is also pinned. This is a manual process at
present, but our dependencies are updated infrequently enough that it's
not introducing any major overhead.

Change-Id: I3cd0c11a1a4eccaf0d77b538cfdb94474833b811
Signed-off-by: Chris Kay <>
2 files changed