Update to use Django 1.7 / 1.8

[aaaaalbert]

The custominstallerbuilder app currently runs on Django 1.6 (which just had its final, end-of-life version released). Django 1.8 will be the new Long-Term Supported version, so this is should be our goal.

(See SeattleTestbed/clearinghouse#152 for potential constraints, and first tests.)

[lukpueh]

+1

Here are some deprecation warning:

[Wed May 18 14:07:05.876024 2016] [wsgi:error] [pid 6105:tid 139860982261504] sys:1: DeprecationWarning: Creating streaming responses with `HttpResponse` is deprecated. Use `StreamingHttpResponse` instead if you need the streaming behavior.
[Wed May 18 14:07:05.876168 2016] [wsgi:error] [pid 6105:tid 139860982261504] 
[Wed May 18 14:20:26.302737 2016] [wsgi:error] [pid 6105:tid 139860906727168] /home/cib/.virtualenvs/cib/lib/python2.7/site-packages/django/http/response.py:330: DeprecationWarning: Using mimetype keyword argument is deprecated, use content_type instead
[Wed May 18 14:20:26.302903 2016] [wsgi:error] [pid 6105:tid 139860906727168]   super(HttpResponse, self).__init__(*args, **kwargs)

[lukpueh]

Some more reasons to update django that I found in my local apache log:

 DeprecationWarning: BaseException.message has been deprecated as of Python 2.6
 DeprecationWarning: Creating streaming responses with `HttpResponse` is deprecated. Use `StreamingHttpResponse` instead if you need the streaming behavior.
 DeprecationWarning: Using mimetype keyword argument is deprecated, use content_type instead
 RemovedInDjango110Warning: django.conf.urls.patterns() is deprecated and will be removed in Django 1.10. Update your urlpatterns to be a list of django.conf.urls.url() instances instead.
 RemovedInDjango110Warning: django.core.context_processors is deprecated in favor of django.template.context_processors.
 RemovedInDjango110Warning: Support for string view arguments to url() is deprecated and will be removed in Django 1.10
 RemovedInDjango110Warning: The context_instance argument of render_to_string is deprecated.
 RemovedInDjango110Warning: You haven't defined a TEMPLATES setting. You must do so before upgrading to Django 1.10. Otherwise Django will be unable to load templates.
 RemovedInDjango19Warning: Default value of 'RedirectView.permanent' will change from True to False in Django 1.9. Set an explicit value to silence this warning.
 RemovedInDjango19Warning: django.utils.importlib will be removed in Django 1.9.
 RemovedInDjango19Warning: The utilities in django.db.models.loading are deprecated in favor of the new application loading system.

Maybe someone could run a command like this on the production system:

sudo cat /var/log/apache2/error.log | grep 'Deprecation\|Removed' | cut -f7,8 -d: | sort | uniq

[lukpueh]

When fixing the problem in #21 I could not replicate the last three Warnings from above log dump.

[aaaaalbert]

Here's the desired grep from alpha-ch (Python 2.7.6, Django 1.8.5):

RemovedInDjango110Warning: django.core.context_processors is deprecated in favor of django.template.context_processors.
 RemovedInDjango110Warning: The context_instance argument of render_to_string is deprecated.
 RemovedInDjango110Warning: You haven't defined a TEMPLATES setting. You must do so before upgrading to Django 1.10. Otherwise Django will be unable to load templates.

That said, #21 looks good and yields a working CIB.

[aaaaalbert]

1.8 compatibility fixed in #21. 1.9/1.10 compatibility is a separate issue.