'pip install pip-requirements-docs.txt dependences' version conflict

[IT-mark]

When I execute

requirementsのpythonモジュールをインストール
pip install --ignore-installed -r /usr/lib/ckan/default/src/ckan/pip-requirements-docs.txt

we get a next version conflict

Paste 1.7.5.1 (/tmp/pip-install-udhle_/paste), Requirement.parse('Paste>=3.0'))

Trace

... writing entry points to pip-egg-info/Paste.egg-info/entry_points.txt
Traceback (most recent call last):
File "", line 1, in
File "/tmp/pip-install-udhle_/paste/setup.py", line 193, in
""",
File "/usr/lib64/python2.7/distutils/core.py", line 152, in setup
dist.run_commands()
File "/usr/lib64/python2.7/distutils/dist.py", line 953, in run_commands
self.run_command(cmd)
File "/usr/lib64/python2.7/distutils/dist.py", line 972, in run_command
cmd_obj.run()
File "/usr/lib/python2.7/site-packages/setuptools/command/egg_info.py", line 271, in run
ep.require(installer=installer)
File "/usr/lib/python2.7/site-packages/pkg_resources/init.py", line 2327, in require
items = working_set.resolve(reqs, env, installer, extras=self.extras)
File "/usr/lib/python2.7/site-packages/pkg_resources/init.py", line 862, in resolve
raise VersionConflict(dist, req).with_context(dependent_req)
pkg_resources.VersionConflict: (Paste 1.7.5.1 (/tmp/pip-install-udhle_/paste), Requirement.parse('Paste>=3.0'))
----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-install-udhle_/paste/

After I tried out changing requirements.txt to paste to 3.0.0 . But then trying to execute "pip install --ignore-installed -r /usr/lib/ckan/default/src/ckan/pip-requirements-docs.txt" I got new conflicts:

httpretty 0.8.3 has requirement urllib3==1.7.1, but you'll have urllib3 1.24.1 which is incompatible.
mox3 0.26.0 has requirement pbr!=2.1.0,>=2.0.0, but you'll have pbr 1.10.0 which is incompatible.

It would be better to solve the problem finding out why the dependence conflict with the paste == 1.7.5.1 version. ¿Can you update pip-requirements-docs.txt dependences?

Thanks