Add suspended_subgroups for testing

This helps test e-mission/e-mission-docs#1104

I am not able to load local configs with the error

```
DEBUG:Received request to join dev-emulator-study
DEBUG: Received request to join dev-emulator-study
DEBUG:Running in dev environment, checking for locally hosted config
DEBUG: Running in dev environment, checking for locally hosted config
DEBUG:About to connect to http://localhost:9090/configs/dev-emulator-study.nrel-op.json
DEBUG: About to connect to http://localhost:9090/configs/dev-emulator-study.nrel-op.json
DEBUG:Local config not found TypeError: Load failed
DEBUG: Local config not found TypeError: Load failed
```

And I can't connect via the debugger (either using Safari or Safari Technology Preview" to see what is going on.

configs/dev-emulator-study.nrel-op.json

@@ -1,6 +1,14 @@
 {
     "version": 1,
     "ts": 1655143472,
+    "opcode": {
+        "autogen": true,
+        "subgroups": [
+          "test",
+          "default"
+        ],
+        "suspended_subgroups": ["default"]
+    },
     "intro": {
         "program_or_study": "study",
         "start_month": "9",