[repo] Drop _get_session method
it's not actually necessary but holds underlying _sessions dict handling.
Drop backward compat relying on it (which IMO should not be a problem).
Drop import of unused QueryError along the way.
[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 = cubicweb_%(cubename)s/migration/*,test/data/*,.tox/*