tox-2.3.0: bug fixes, new plugin hooks

[holger krekel]

Just released tox-2.3.0, the python test configuration and automation tool.
It brings some important bug fixes and more hooks related to testenvironment
creation and installation, allowing upcoming plugins like tox-debian to add
extra steps during installation.

I'd like to send special thanks to the Tryton foundation who organized
some funding in order to tackle the proper fixing of a serious
regression of tox-2.2 (see changelog below).  thanks also to David Stanek,
Julien Castets, Nelfin for their contributions.

You'll find the current docs for tox here:

    https://testrun.org/tox/latest/

and have fun,
holger krekel

-- 
about me:    http://holgerkrekel.net/about-me/
contracting: http://merlinux.eu


2.3.0
-----

- DEPRECATE use of "indexservers" in tox.ini.  It complicates
  the internal code and it is recommended to rather use the
  devpi system for managing indexes for pip.

- fix issue285: make setenv processing fully lazy to fix regressions
  of tox-2.2.X and so that we can now have testenv attributes like 
  "basepython" depend on environment variables that are set in 
  a setenv section. Thanks Nelfin for some tests and initial
  work on a PR.

- allow "#" in commands.  This is slightly incompatible with commands
  sections that used a comment after a "\" line continuation.
  Thanks David Stanek for the PR.

- fix issue289: fix build_sphinx target, thanks Barry Warsaw.

- fix issue252: allow environment names with special characters.
  Thanks Julien Castets for initial PR and patience.

- introduce experimental tox_testenv_create(venv, action) and 
  tox_testenv_install_deps(venv, action) hooks to allow
  plugins to do additional work on creation or installing
  deps.  These hooks are experimental mainly because of
  the involved "venv" and session objects whose current public 
  API is not fully guranteed.

- internal: push some optional object creation into tests because
  tox core doesn't need it.