Added health check for web

tbot/web/app.py

@@ -15,6 +15,7 @@ def App():
             (r'/(favicon.ico)', web.StaticFileHandler, 
                 {"path": os.path.join(os.path.dirname(__file__), 'static')}),
 
+            (r'/health', handlers.health.Handler),
             (r'/twitch/login', handlers.api.twitch.oauth.Login_handler),
             (r'/twitch/logout', handlers.api.twitch.oauth.Logout_handler),
             (r'/connect/twitch', handlers.api.twitch.oauth.Handler),

tbot/web/handlers/__init__.py

@@ -2,4 +2,5 @@
     react,
     api,
     twitch,
+    health,
 )

tbot/web/handlers/health.py

@@ -0,0 +1,12 @@
+from tornado.web import RequestHandler
+
+class Handler(RequestHandler):
+
+    async def get(self):
+        self.set_header('Content-Type', 'text/plain')
+        if hasattr(self.application, 'shutting_down') and self.application.shutting_down == True:
+            self.write('SHUTTING DOWN')
+            self.set_status(503)
+            return
+        self.set_status(200)
+        self.write('READY')