Bump required version of Django to 1.10

Since Debian testing now has Django 1.10.  There is no necessity to
support older versions of Django.  The fix for showing menu items does
depend on a small feature that is introduced in Django 1.10:
django.setup(set_prefix=True) and FORCE_SCRIPT_NAME.

.travis.yml

@@ -5,9 +5,7 @@ sudo: required
 language: generic
 
 env:
-  - DJANGO_VERSION=">=1.7.0,<1.8.0"
-  - DJANGO_VERSION=">=1.8.0,<1.9.0"
-  - DJANGO_VERSION=">=1.9.0"
+  - DJANGO_VERSION=">=1.10.0"
 
 # Debian packages required
 before_install:

setup.py

@@ -180,7 +180,7 @@ setuptools.setup(
     setup_requires=['setuptools-git'],
     install_requires=[
         'cherrypy >= 3.0',
-        'django >= 1.7.0',
+        'django >= 1.10.0',
         'django-bootstrap-form',
         'django-stronghold',
         'psutil',