Pyee's add_listener() method was not added until release 9.0.0. Bumble's
setup.cfg specifies a minimum pyee version of 8.2.2.
Remove the call to add_listener() in l2cap.py. If the add_listener() API
is prefered over the on(), another solution would be to bump the pyee
version requirement.
[85542e0] fix test
[3748781] add ASAH sink example
[e782e29] add app
[83daa30] wip
[7f138a0] add test
[f732108] allow different address syntax
[9d0bbf8] rename deprecated methods
[eb303d5] add LE CoC support