Invalid Django version in requirements.txt file

[Jean-Sebastien Bevilacqua]

In requirements.txt file, Django version is set to :
Django<1.9,>=1.7

During my tests, all Django versions below 1.8 print this stacktrace when running the server :

Traceback (most recent call last):
  File "manage.py", line 25, in <module>
    execute_from_command_line(sys.argv)
  File "/home/T0143947/GIT/app-catalog/.venv/local/lib/python2.7/site-packages/django/core/management/__init__.py", line 385, in execute_from_command_line
    utility.execute()
  File "/home/T0143947/GIT/app-catalog/.venv/local/lib/python2.7/site-packages/django/core/management/__init__.py", line 354, in execute
    django.setup()
  File "/home/T0143947/GIT/app-catalog/.venv/local/lib/python2.7/site-packages/django/__init__.py", line 21, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "/home/T0143947/GIT/app-catalog/.venv/local/lib/python2.7/site-packages/django/apps/registry.py", line 108, in populate
    app_config.import_models(all_models)
  File "/home/T0143947/GIT/app-catalog/.venv/local/lib/python2.7/site-packages/django/apps/config.py", line 202, in import_models
    self.models_module = import_module(models_module_name)
  File "/usr/lib/python2.7/importlib/__init__.py", line 37, in import_module
    __import__(name)
  File "/home/T0143947/GIT/app-catalog/.venv/local/lib/python2.7/site-packages/compressor/models.py", line 1, in <module>
    from compressor.conf import CompressorConf # noqa
  File "/home/T0143947/GIT/app-catalog/.venv/local/lib/python2.7/site-packages/compressor/conf.py", line 5, in <module>
    from django.template.utils import InvalidTemplateEngineError
ImportError: No module named utils

I propose to set the Django minimum version to 1.8.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/280555

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/280555
Committed: https://git.openstack.org/cgit/openstack/app-catalog/commit/?id=0f9664e7953532a455c483fd5c66fa57ccfc5b49
Submitter: Jenkins
Branch: master

commit 0f9664e7953532a455c483fd5c66fa57ccfc5b49
Author: Jean-Sebastien Bevilacqua <email address hidden>
Date: Tue Feb 16 09:54:34 2016 +0100

    Fix Django version in requirements.txt

    Django must be at least to 1.8 version to avoid stacktrace
    when starting server.

    Closes-Bug: #1545982
    Change-Id: I62b46535794f8cb98c03e6fa30a04f382242ef76