Support for starting without epmd

[bsedat]

We had previously noticed that the epmd process was left running on user systems after the CLI exited, and we have a workaround in the elixir application's release to start without epmd (OTP 23+):

1. Create a rel/env.bat.eex, rel/env.sh.eex which set RELEASE_DISTRIBUTION=none
2. Create a rel/vm.args.eex to set -start_epmd false

Perhaps this is something we can support in Burrito via configuration to the wrapper.

[ashea-code]

I wonder if we should default to starting epmd or default to NOT starting epmd if we expose this option

[josevalim]

Step 2 may not be necessary. -start_epmd only has an effect if the release has a name. :)