Update WSGI entrypoint to match standard Django

www/wsgi.py

@@ -0,0 +1,7 @@
+import os
+
+from django.core.wsgi import get_wsgi_application
+
+os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'conservancy.settings')
+
+application = get_wsgi_application()

www/wsgicustom.wsgi

@@ -1,14 +0,0 @@
-#!/usr/bin/env python
-
-import os
-import sys
-
-# Work around <https://bugs.python.org/issue7980>
-import _strptime
-
-root_dir = os.path.abspath(os.path.dirname(__file__))
-sys.path.insert(0, root_dir)
-os.environ['DJANGO_SETTINGS_MODULE'] = 'conservancy.settings'
-
-from django.core.wsgi import get_wsgi_application
-application = get_wsgi_application()