Limit pytest<3.3 for Python 2.6 support

[joshmoore]

https://pypi.python.org/pypi/attrs/17.3.0 mentions
Python3 and backware-incompatible changes. Trying
to restrict it after a failed Jenkins jobs:

https://ci.openmicroscopy.org/view/Failing/job/SCC-merge/933/console

[sbesson]

Thanks. Is it worth a patch release or are these changes only affecting the testing infrastructure of the library?

[joshmoore]

I wasn't sure where the attrs dependency came in. Trying out pipdeptree before python setup.py test:

bin/pipdeptree
pipdeptree==0.10.1
  - pip [required: >=6.0.0, installed: 9.0.1]
scc==0.8.0-3-g63f4
  - argparse [required: Any, installed: 1.1]
  - PyGithub [required: Any, installed: 1.35]
    - pyjwt [required: Any, installed: 1.5.3]
  - yaclifw [required: >=0.1.2, installed: 0.1.2]
    - argparse [required: Any, installed: 1.1]
setuptools==3.6

and after:

bin/pipdeptree
nose==1.3.4
numpy==1.9.1
Pillow==3.1.1
pipdeptree==0.10.1
  - pip [required: >=6.0.0, installed: 9.0.1]
setuptools==38.2.3
virtualenv==1.11.6
wheel==0.29.0

and after pip install flake8:

bin/pipdeptree e8
flake8==3.5.0
  - configparser [required: Any, installed: 3.5.0]
  - enum34 [required: Any, installed: 1.1.6]
  - mccabe [required: <0.7.0,>=0.6.0, installed: 0.6.1]
  - pycodestyle [required: >=2.0.0,<2.4.0, installed: 2.3.1]
  - pyflakes [required: <1.7.0,>=1.5.0, installed: 1.6.0]
nose==1.3.4
numpy==1.9.1
Pillow==3.1.1
pipdeptree==0.10.1
  - pip [required: >=6.0.0, installed: 9.0.1]
setuptools==38.2.3
virtualenv==1.11.6
wheel==0.29.0

Still not sure. I triggered https://travis-ci.org/openmicroscopy/snoopycrimecop/builds/311204896 but that'll just fail on flake8. Probably would require manual testing if we want to prove to ourselves that it's testing only. Might be easiest to just tag & bump.

[sbesson]

Introduced in pytest-dev/pytest#2641 it seems. So it we are capping below pytest 3.3.0 we might not need it.

[joshmoore]

Force-pushed away the attrs commits.

[sbesson]

https://ci.openmicroscopy.org/job/SCC-merge/935/ is green with these changes so LGTM. Two questions:

• should we/you/I update the PR title/description to match the capping?
• is this and flake8: remove bare excepts #223 worth a patch release or should we consider them as internal/testing only?

[joshmoore]

Title fixed. Merging. I'm happy for there to be an 0.8.1 but considering this is really only pytest related, I'm just as happy to leave it on master.

[sbesson]

Agreed, I also could not convince myself we need to cut a patch release at this point in time, so holding off and we can move forward with the release if necessary.