gnu: Remove python-pytest@2.

* gnu/packages/python.scm (python-pytest): Update to 3.0.7.
[source]: Move substitution to ...
[arguments]: ... here. Incorporate phase from pytest-3.0.
[native-inputs]: Add PYTHON-HYPOTHESIS.
(python-pytest-3.0): Remove variable.
(python2-pytest-3.0): Rename to ...
(python2-pytest): ... this.
[native-inputs]: Add PYTHON2-ENUM34.
* gnu/packages/backup.scm (borg)[native-inputs]: Replace PYTHON-PYTEST-3.0
with PYTHON-PYTEST.
* gnu/packages/calendar.scm (khal): Likewise.
* gnu/packages/databases.scm (python-orator): Likewise.
* gnu/packages/python.scm (python-sphinx-1.6, python-sphinx-1.5.3,
python-pexpect, python-cryptography, python-pyopenssl, python-pytest-warnings,
python-pytest-capturelog, python-pytest-catchlog, python-marshmallow,
python-apispec, python-flasgger, python-pyjwt, python-grako,
python-honcho): Likewise.
* gnu/packages/web.scm (python-internetarchive): Likewise.

gnu: python-six: Update to 1.11.0.

* gnu/packages/python.scm (python-six): Update to 1.11.0.

gnu: python-six: Really enable tests.

* gnu/packages/python.scm (python-six)[arguments]: Override 'check' phase.

gnu: python-py: Update to 1.4.34.

* gnu/packages/python.scm (python-py, python2-py): Update to 1.4.34.

gnu: python@3: Update to 3.6.3.

* gnu/packages/patches/python-3.5-fix-tests.patch: Rename to ...
* gnu/packages/patches/python-3-fix-tests.patch: ... this. Adjust and disable
more tests.
* gnu/packages/patches/python-3.5-getentropy-on-old-kernels.patch: Delete file.
* gnu/local.mk (dist_patch_DATA): Adjust accordingly.
* gnu/packages/python.scm (python-2.7)[argument]: Patch '/bin/sh' in one more file.
(python-3.5): Rename to ...
(python-3.6): ... this. Update to 3.6.3.
[source](patches): Remove obsolete patch, adjust to patch rename.
(python-3): Use PYTHON-3.6.

gnu: python@2: Update to 2.7.14.

* gnu/packages/python.scm (python-2.7): Update to 2.7.14.
[source]: Add patch to skip two new tests.  Delete upstreamed patch.
* gnu/packages/patches/python-2.7-adjust-tests.patch: New file.
* gnu/packages/patches/python-2.7-getentropy-on-old-kernels.patch: Delete file.
* gnu/local.mk (dist_patch_DATA): Adjust accordingly.

Revert "gnu: python-pyatspi: Update to 2.26.0."

This reverts commit 629f33e233c34235ed74a1b12ac38a3f58a99eea, which breaks
orca@3.26.0.

gnu: f-seq: Fix location of commons-cli.jar.

* gnu/packages/bioinformatics.scm (f-seq)[arguments]: Fix location of
commons-cli.jar in the wrapper script.

gnu: eog-plugins: Update to 3.26.1.

* gnu/packages/gnome.scm (eog-plugins): Update to 3.26.1.

gnu: eog: Update to 3.26.1.

* gnu/packages/gnome.scm (eog): Update to 3.26.1.

gnu: python-pyatspi: Update to 2.26.0.

* gnu/packages/gnome.scm (python-pyatspi): Update to 2.26.0.

gnu: btrfs-progs: Update to 4.13.3.

* gnu/packages/linux.scm (btrfs-progs): Update to 4.13.3.

gnu: hplip: Update to 3.17.10.

* gnu/packages/cups.scm (hplip): Update to 3.17.10.

gnu: mailutils: Update to 3.3.

* gnu/packages/mail.scm (mailutils): Update to 3.3.
[arguments]: Rename 'pre-build' phase to 'prepare-test-suite', and move
after 'check'.  Set 'HOME', and create ~/.mh_profile.

gnu: perl-crypt-random-source: Use 'perl-license'.

* gnu/packages/crypto.scm (perl-crypt-random-source)[license]: Change to
LICENSE:PERL-LICENSE.

gnu: Add atool.

* gnu/packages/compression.scm (atool): New variable.

Co-authored-by: Ricardo Wurmus <rekado@elephly.net>

gnu: mupdf: Fix CVE-2017-15587.

* gnu/packages/patches/mupdf-CVE-2017-15587.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.
* gnu/packages/pdf.scm (mupdf)[source](patches): Use it.

gnu: python-protobuf: Update to 3.4.0.

* gnu/packages/protobuf.scm (python-protobuf): Update to 3.4.0.

gnu: Add protobuf-c.

* gnu/packages/protobuf.scm (protobuf-c): New variable.

gnu: protobuf: Update to 3.4.1.

* gnu/packages/protobuf.scm (protobuf): Update to 3.4.1.