Remove old comment

Author: astrofrog

setup.cfg

@@ -23,10 +23,6 @@ long_description = file: README.rst
 [options]
 zip_safe = True
 packages = find:
-# Note that we don't include Matplotlib as a required dependency since it is only
-# required if the plugin is actually used, in which case the package using this
-# will already need to have Matplotlib declared as a dependency. We want to avoid
-# installing Matplotlib unecessarily.
 install_requires =
     pytest
     matplotlib