Get IP Pool details API call

We released a small update to our /ip_pools endpoint to allow a user to issue a GET call to https://api.mailgun.net/v1/ip_pools/<pool_id> to be able to retrieve information about the IP Pool such as which IPs and domains are associated with that IP Pool, along with the usual name and description.

We released a small update to our /ip_pools endpoint to allow a user to issue a GET call to https://api.mailgun.net/v1/ip_pools/<pool_id> to be able to retrieve information about the IP Pool such as which IPs and domains are associated with that IP Pool, along with the usual name and description.