docs build failing on psycopg2 dependency

[Matt Riedemann]

https://review.opendev.org/#/c/689152/ re-introduced using the requirements.txt file during docs builds which it shouldn't be because it installs things like psycopg2 which we don't need and that's failing now:

https://zuul.opendev.org/t/openstack/build/10344924bca44849b06b8fae29b5494f/log/job-output.txt#652

2019-10-25 13:58:32.599585 | ubuntu-bionic | Downloading http://mirror.gra1.ovh.openstack.org/pypifiles/packages/12/67/5d953cb20497d4f56965bc5bcf03134244be7bae4eb2b1f7ca5cf31b245f/os_xenapi-0.3.4-py2.py3-none-any.whl (137kB)

2019-10-25 13:58:32.599697 | ubuntu-bionic | Collecting psycopg2===2.8.4 (from -c /home/zuul/src/opendev.org/openstack/requirements/upper-constraints.txt (line 97))

2019-10-25 13:58:32.599851 | ubuntu-bionic | Downloading http://mirror.gra1.ovh.openstack.org/pypifiles/packages/84/d7/6a93c99b5ba4d4d22daa3928b983cec66df4536ca50b22ce5dcac65e4e71/psycopg2-2.8.4.tar.gz (377kB)

2019-10-25 13:58:32.599905 | ubuntu-bionic | ERROR: Command errored out with exit status 1:

2019-10-25 13:58:32.600316 | ubuntu-bionic | command: /home/zuul/src/opendev.org/openstack/nova/.tox/docs/bin/python -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/tmp/pip-install-ki5_j1sg/psycopg2/setup.py'"'"'; __file__='"'"'/tmp/pip-install-ki5_j1sg/psycopg2/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' egg_info --egg-base pip-egg-info

2019-10-25 13:58:32.600384 | ubuntu-bionic | cwd: /tmp/pip-install-ki5_j1sg/psycopg2/

2019-10-25 13:58:32.600421 | ubuntu-bionic | Complete output (7 lines):

2019-10-25 13:58:32.600449 | ubuntu-bionic | running egg_info

2019-10-25 13:58:32.600496 | ubuntu-bionic | creating pip-egg-info/psycopg2.egg-info

2019-10-25 13:58:32.600551 | ubuntu-bionic | writing pip-egg-info/psycopg2.egg-info/PKG-INFO

2019-10-25 13:58:32.600631 | ubuntu-bionic | writing dependency_links to pip-egg-info/psycopg2.egg-info/dependency_links.txt

2019-10-25 13:58:32.600706 | ubuntu-bionic | writing top-level names to pip-egg-info/psycopg2.egg-info/top_level.txt

2019-10-25 13:58:32.600780 | ubuntu-bionic | writing manifest file 'pip-egg-info/psycopg2.egg-info/SOURCES.txt'

2019-10-25 13:58:32.600936 | ubuntu-bionic | Error: b'You need to install postgresql-server-dev-X.Y for building a server-side extension or libpq-dev for building a client-side application.\n'

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/691391

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/691391
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=b2122f77024f071a78f0b73a3f3336dbd1b8bcac
Submitter: Zuul
Branch: master

commit b2122f77024f071a78f0b73a3f3336dbd1b8bcac
Author: Matt Riedemann <email address hidden>
Date: Fri Oct 25 12:37:38 2019 -0400

    Stop building docs with (test-)requirements.txt

    Change Iba797243d2a137b551223165a1af1a8676bcea02 was a bit
    overzealous in using {[testenv]deps} and changed the docs
    tox target to also install requirements.txt and
    test-requirements.txt which means for docs builds we're
    installing things like psycopg2 which we shouldn't be doing
    if we don't have the correct native packages installed to
    build those types of dependencies.

    Change-Id: Ib718911596b93ec6ec7e899210300d2f0d9572ed
    Closes-Bug: #1849870