Enable heartbeats by default #142
Description
Disabled heartbeats is not a great default.
Default values in the 10-20 seconds range work well for a lot of users. Some other clients, e.g. Bunny, are configured to use server value by default, which still leaves heartbeats enabled.
This is particularly useful with a recent change in 3.6.0 server, rabbitmq/rabbitmq-server#384.