Add matplotlib as a docs dependency

eerovaher · eerovaher · commit 9233fddffcbd · 2022-05-03T14:18:58.000+02:00
The documentation already contains plots, so `matplotlib` is required
for building it. `matplotlib` does not have to be explicitly listed in
the 'all' dependencies because it is included indirectly through
`aplpy`.
diff --git a/setup.cfg b/setup.cfg
@@ -169,6 +169,7 @@ test=
    flask
    pytest-dependency
 docs=
+   matplotlib
    sphinx-astropy>=1.5
    scipy
 all=
