Run puma cli server in unbundled env in worker gem tests [changelog skip] (#2478)
Run puma cli server in unbundled env in worker gem tests [changelog skip] (#2478)

* Run puma cli server in unbundled env in worker gem tests

Running `puma` in a clean bundler env is a more realistic way to start
puma.

* Install gems to release directory in worker gem tests
puma/puma,eileencodes/puma,puma/puma,puma/puma,puma/puma,eileencodes/puma,eileencodes/puma,eileencodes/puma