allow other genserver return values

[spencerdcarlson]

I ran into a case where I wanted to return :ignore in my Vault init/1 callback, but the strict match on {:ok, pid} was causing the supervisor to crash.

[coveralls]

Coverage: 98.0% (-1.0%) from 98.98% when pulling 8b8e156e216e91ae2278680a0f4f4a6804210c10 on spencerdcarlson:master into 404727b1b81b60cbbbb5441e72d45ca391e365a0 on danielberkompas:master.

[coveralls]

Coverage: 98.0% (-1.0%) from 98.98% when pulling 8b8e156e216e91ae2278680a0f4f4a6804210c10 on spencerdcarlson:master into 404727b1b81b60cbbbb5441e72d45ca391e365a0 on danielberkompas:master.

[danielberkompas]

Thanks! ⭐