Update source style to match current settings from black

[yt-ms]

Problem description

From a clean checkout, running make qa reformats a bunch of files, presumably because the version of Black has moved on.

Code Sample

E.g. in test_workspace_io.py:

@pytest.mark.parametrize(
    "example, filename", [("getting_started", "GettingStarted.json"),],
)

becomes

@pytest.mark.parametrize(
    "example, filename",
    [
        ("getting_started", "GettingStarted.json"),
    ],
)

Context

System Information
==================
OS         Windows
OS-release      10
Python       3.7.5

Package Versions
================
depinfo                1.5.4
httpx                 0.15.3
ordered-set              3.1
pip                   20.2.3
pydantic               1.6.1
python-dotenv         0.14.0
setuptools            41.2.0
structurizr-python 0+unknown

[Midnighter]

I've pushed a commit that introduces all those style changes. You probably will have to rebase #25

[yt-ms]

Thanks!