Merge "always use pip constraints" into stable/liberty

tox.ini

@@ -9,7 +9,7 @@ envlist = py27,pep8
 setenv = VIRTUAL_ENV={envdir}
          PYTHONHASHSEED=0
 usedevelop = True
-install_command = pip install {opts} {packages}
+install_command = pip install -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt?h=stable/liberty} {opts} {packages}
 
 deps = -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
@@ -27,6 +27,10 @@ passenv = http_proxy HTTP_PROXY https_proxy HTTPS_PROXY no_proxy NO_PROXY
 downloadcache = ~/cache/pip
 
 [testenv:releasenotes]
+# NOTE(jaegerandi): This target does not use constraints because
+# upstream infra does not yet support it. Once that's fixed, we can
+# drop the install_command.
+install_command = pip install -U --force-reinstall {opts} {packages}
 commands = sphinx-build -a -E -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
 
 [testenv:py34]
@@ -125,6 +129,10 @@ commands = bash tools/lintstack.sh
 [testenv:cover]
 # Also do not run test_coverage_ext tests while gathering coverage as those
 # tests conflict with coverage.
+# NOTE(jaegerandi): This target does not use constraints because
+# upstream infra does not yet support it. Once that's fixed, we can
+# drop the install_command.
+install_command = pip install -U --force-reinstall {opts} {packages}
 commands =
   python setup.py testr --coverage \
     --testr-args='^(?!.*test.*coverage).*$'
@@ -135,6 +143,10 @@ envdir = {toxworkdir}/venv
 commands = {toxinidir}/tools/config/generate_sample.sh from_tox
 
 [testenv:venv]
+# NOTE(jaegerandi): This target does not use constraints because
+# upstream infra does not yet support it. Once that's fixed, we can
+# drop the install_command.
+install_command = pip install -U --force-reinstall {opts} {packages}
 commands = {posargs}
 
 [testenv:docs]