[pkg] Add missing entries to MANIFEST.in
Detected by running `check-manifest
<https://github.com/mgedmin/check-manifest>`_. Add a tox environment
accordingly.
Closes #15229018.
[tox]
envlist = py27,py34,flake8
[testenv]
sitepackages = true
deps =
pytest
commands =
{envpython} -m pytest {posargs:test}
[testenv:flake8]
skip_install = true
whitelist_externals =
flake8
deps =
flake8
commands = flake8
[flake8]
exclude = migration/*,test/data/*,setup.py,.tox/*