Cannot start test agents with ngrok anymore, ngrok now requires an authtoken

[nodlesh]

Errors generated when trying to start test agent containers with the -n flag, as in

AGENT_CONFIG_FILE=/aries-backchannels/acapy/auto_issuer_config.yaml ./manage start -a acapy-main -b acapy-main -n

ERROR:  authentication failed: Usage of ngrok requires a verified account and authtoken.
ERROR:  
ERROR:  Sign up for an account: https://dashboard.ngrok.com/signup
ERROR:  Install your authtoken: https://dashboard.ngrok.com/get-started/your-authtoken
ERROR:  
ERROR:  ERR_NGROK_4018
ERROR:  

AATH will have to be updated to use an authtoken with ngrok usage. A few restrictions with free ngrok to consider.
1/ Only one ngrok container can be stood up with the authtoken. This means, even with an authtoken integrated into AATH, only one container can run with ngrok. This is not viable for usage with wallet testing, since there are two test agents started with ngrok.
2/ An option is to run one ngrok container, and start multiple ngrok services in that one container to service the 1-n agents running. However, an authtoken can only run 3 sessions at a time, so if anyone needs more than 3 agents with ngrok then this solution will not work for them. In this case the user would need a paid ngrok authtoken to use the AATH. This more than 2 agent case will probably be rare.