permit LTI auth requests through basic auth

playbooks/roles/nginx/templates/edx/app/nginx/sites-available/lms.j2

@@ -139,11 +139,17 @@ error_page {{ k }} {{ v }};
     try_files $uri @proxy_to_lms_app;
   }
 
-  # No basic auth security on oath2 endpoint
+  # No basic auth security on oauth2 endpoint
   location /oauth2 {
     try_files $uri @proxy_to_lms_app;
   }
 
+  # No basic auth security on third party auth endpoints
+  location /auth {
+    try_files $uri @proxy_to_lms_app;
+  }
+
+
   # No basic auth security on the heartbeat url, so that ELB can use it
   location /heartbeat {
     try_files $uri @proxy_to_lms_app;