Add "Cache-Control: no-cache" for redirects to badges

Related #1612

readthedocs/projects/views/public.py

@@ -15,6 +15,7 @@
 from django.http import HttpResponse, HttpResponseRedirect, Http404
 from django.shortcuts import get_object_or_404, render_to_response
 from django.template import RequestContext
+from django.views.decorators.cache import cache_control
 from django.views.generic import ListView, DetailView
 from django.utils.datastructures import SortedDict
 from django.views.decorators.cache import cache_page
@@ -120,6 +121,7 @@ def _badge_return(redirect, url):
 
 # TODO remove this, it's a temporary fix to heavy database usage
 @cache_page(60 * 30)
+@cache_control(no_cache=True)
 def project_badge(request, project_slug, redirect=True):
     """Return a sweet badge for the project"""
     version_slug = request.GET.get('version', LATEST)