* gnu/packages/python.scm (python-pylint): Update to 1.7.2.
[native-inputs]: Add PYTHON-PYTEST and PYTHON-PYTEST-RUNNER.

* gnu/packages/python.scm (python-astroid): Update to 1.5.3.
[properties]: Declare python2 variant.
(python2-astroid)[propagated-inputs]: Add PYTHON2-BACKPORTS-FUNCTOOLS-LRU-CACHE,
PYTHON2-ENUM34 and PYTHON2-SINGLEDISPATCH.

* gnu/packages/python.scm (python-pyopenssl, python2-pyopenssl): Update to 17.1.0.
[source]: Remove patch.
[native-inputs]: Add PYTHON-PRETEND.
[arguments]<#:phases>: Disable the network test here instead of via a patch.
Also disable one new test.
* gnu/packages/patches/python-pyopenssl-skip-network-test.patch: Delete file.
* gnu/local.mk (dist_patch_DATA): Remove it.

* gnu/packages/python.scm (python-cryptography-vectors): Update to 1.9.
(python-cryptography): Update to 1.9.
[propagated-inputs]: Remove PYTHON-PACKAGING.

* gnu/packages/python.scm (python-cffi): Update to 1.10.0.
[arguments]<#:phases>: Patch distutils.ccompiler call to use "gcc". Patch
another hard-coded cc invocation. Adjust `py.test` invocation per README.

* gnu/packages/python.scm (python-cffi, python2-cffi)[arguments]: Replace
'check' phase with custom expression. Change to 'modify-phases' syntax.

* gnu/packages/python.scm (python-vobject, python2-vobject): Update to 0.9.5.

* gnu/packages/python.scm (snakemake)[arguments]: Add build phase
"call-wrapper-not-wrapped-snakemake".

* gnu/packages/python.scm (python-rencode): New variable.

Co-authored-by: Ludovic Courtès <ludo@gnu.org>

* gnu/packages/python.scm (python2-pyopengl): New variable.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>