Log Message:
py-pluggy: updated to 0.9.0

pluggy 0.9.0

Features
- PluginManager.load_setuptools_entrypoints now accepts a name parameter that \ 
when given will
  load only entry points with that name.

  PluginManager.load_setuptools_entrypoints also now returns the number of \ 
plugins loaded by the
  call, as opposed to the number of all plugins loaded by all calls to this method.

Bug Fixes
- Fix internal varnames function for PyPy3.