Log Message:
py-tox: updated to 3.5.3

v3.5.3:

Bugfixes
- Fix bug with incorrectly defactorized dependencies
- do the same transformation to egg_info folders that pkg_resources does;
  this makes it possible for hyphenated names to use the develop-inst-noop \ 
optimization (cf. 910),
  which previously only worked with non-hyphenated egg names
- previously, if a project's setup.py --name emitted extra information to
  stderr, tox would capture it and consider it part of the project's name; now,
  emissions to stderr are printed to the console
- change the way we acquire interpreter information to make it compatible with \ 
jython interpreter, note to create jython envs one needs virtualenv > 16.0 \ 
which will be released later

Documentation
- document substitutions with additional content starting with a space cannot be \ 
alone on a line inside the ini file
- change the spelling of a single word from contrains to the proper word, constraints
- Mention the minimum version required for commands_pre/commands_post support.