This workaround is not needed anymore, thanks to p1_pgsql 3bf645b,
included in p1_pgsql 1.1.13, and used in ejabberd 21.12.
This reverts commit 964cb3aaca.
It supports all that was already in .travis.yml and tests.yml, plus:
- exclude paths that don't affect source code
- two very distinct scenarios, ancient a recent (OTP, Rebar, Ubuntu)
- cache binaries and dialyzer for small speedup and network usage
- separated results, to view comfortably where and what failed
- use coveralls example rebar3 code, instead of custom rebar2
- upload binaries.zip that can be used with Binary Installers