9.6rc1 Background worker starting multiple times

Running into an issue with pg_partman's (version 2.6.0) background worker process with 9.6rc1.

https://github.com/keithf4/pg_partman/tree/master/test/test_bgw

Noticed the issue when a user ran the pgtap tests against it and I'm seeing the same thing as well. It's working fine with 9.4 and 9.5. Looking in the postgresql logs it seems to be trying to start the initial background worker process multiple times and then one of them fails to start properly which then causes issues when maintenance tries to run. I've attached the postgresql log file from when 9.5 starts up (95_postgresql-2016-09-15_180306.log) and things are working normally and another log file from 9.6 (96_postgresql-2016-09-15_180131.log) that shows the odd startup behavior