Redis/Sentinel cluster failover results in "failover-abort-not-elected master"

Ignore me on the instance ID confusion, that's my fault - I forgot that the sentinels were voting for a leader among the sentinels, not voting for a new master among the candidates, so the three different IDs makes sense.

So, here's the real problem:

master0:name=resque,status=ok,address=192.168.56.103:6379,slaves=0,sentinels=3

There's no slaves there that the sentinels have noticed, so they don't have a good node to make live during the vote.

Check the slaveof config on the 192.168.56.103:6380 instance, make sure that instance is running, and connect to it to check its info to verify that it's slaving. Once the 192.168.56.103:6379 sees it as a slave (in its info command), the sentinels will pick it up as a known slave and be able to fail over to it.