Allow running web app via ASGI

rattail_demo/web/app.py

@@ -3,8 +3,6 @@
 Pyramid web application
 """
 
-from __future__ import unicode_literals, absolute_import
-
 from tailbone import app
 from tailbone_corepos.db import CoreOfficeSession, CoreTransSession
 
@@ -40,3 +38,12 @@ def main(global_config, **settings):
                              under='pyramid_tm.tm_tween_factory')
 
     return pyramid_config.make_wsgi_app()
+
+
+def asgi_main():
+    """
+    This function returns an ASGI application.
+    """
+    from tailbone.asgi import make_asgi_app
+
+    return make_asgi_app(main)