gnu: Add python2-pytest-cache.

* gnu/packages/python.scm (python2-pytest-cache): New variable.
(python-pytest-cache)[properties]: New field.

gnu: python2-pythondialog: Update to 3.4.0.

* gnu/packages/python.scm (python2-pythondialog): Update to 3.4.0.
[source]: Use pypi-uri.

Co-authored-by: Leo Famulari <leo@famulari.name>

gnu: Add python-urwidtrees.

* gnu/packages/python.scm (python-urwidtrees, python2-urwidtrees):
New variables.

Signed-off-by: Leo Famulari <leo@famulari.name>

gnu: python-sphinx-repoze-autointerface: Update to 0.8.

* gnu/packages/python.scm (python-sphinx-repoze-autointerface,
python2-sphinx-repoze-autointerface): Update to 0.8.

gnu: python-cryptography, python-cryptography-vectors: Update to 1.3.4.

* gnu/packages/python.scm (python-cryptography, python2-cryptography):
Update to 1.3.4.
[source]: Use pypi-uri.
(python-cryptography-vectors, python2-cryptography-vectors): Update to 1.3.4.
[source]: Use pypi-uri.

gnu: Add python-prompt-toolkit.

* gnu/packages/python.scm (python-prompt-toolkit, python2-prompt-toolkit):
New variables.

Signed-off-by: Leo Famulari <leo@famulari.name>

gnu: python-wcwidth: Add missing 'properties' field.

This is a followup to commit a44fd439dcef88b33c00db94fb3419e097401fee.

* gnu/packages/python.scm (python-wcwidth)[properties]: New field.

gnu: python2-orator: Rearrange inputs.

* gnu/packages/python.scm (python2-orator)[native-inputs]: Move
python2-ipaddress ...
[propagated-inputs]: to here.

gnu: python-orator: Rearrange inputs.

* gnu/packages/python.scm (python-orator)[native-inputs]: Move
python-arrow, python-blinker, python-cleo, python-fake-factory,
python-inflection, python-lazy-object-proxy, python-pyaml,
python-simplejson, python-wrapt ...
[propagated-inputs]: to here.

gnu: python2-fake-factory: Rearrange inputs.

* gnu/packages/python.scm (python2-fake-factory)[native-inputs]: Move
python2-ipaddress ...
[propagated-inputs]: to here.

gnu: python-fake-factory: Rearrange inputs.

* gnu/packages/python.scm (python-fake-factory)[native-inputs]: Move
python-dateutil-2, python-six ...
[propagated-inputs]: to here.

gnu: python-email-validator: Rearrange inputs.

* gnu/packages/python.scm (python-email-validator)[native-inputs]: Move
python-dnspython, python-idna ...
[propagated-inputs]: to here.

gnu: python-cleo: Rearrange inputs.

* gnu/packages/python.scm (python-cleo)[native-inputs]: Move
python-psutil, python-pylev ...
[propagated-inputs]: to here.

gnu: python-arrow: Rearrange inputs.

* gnu/packages/python.scm (python-arrow)[native-inputs]: Move
python-dateutil-2 ...
[propagated-inputs]: to here.

gnu: python-pykafka: Rearrange inputs.

* gnu/packages/python.scm (python-pykafka)[native-inputs]: Move
python-gevent, python-kazoo, python-tabulate ...
[propagated-inputs]: to here.

gnu: python-kazoo: Rearrange inputs.

* gnu/packages/python.scm (python-kazoo)[native-inputs]: Move
six ...
[propagated-inputs]: to here.

gnu: python-twisted: Rearrange inputs.

* gnu/packages/python.scm (python-twisted)[native-inputs]: Move
python-zope-interface ...
[propagated-inputs]: to here.

gnu: Add python-orator and python2-orator.

* gnu/packages/python.scm (python-orator, python2-orator): New variables.

gnu: Add python-flexmock and python2-flexmock.

* gnu/packages/python.scm (python-flexmock, python2-flexmock): New variables.

gnu: Add python-pyaml and python2-pyaml.

* gnu/packages/python.scm (python-pyaml, python2-pyaml): New variables.