Switch to built-in Erlang logger

[michaelklishin]

Back in the days when Cuttlefish was first invented, Erlang's built-in logger left a lot to be desired and Lager was a natural choice.

These days OTP logger provides a lot of relevant features, is not prone to overload (not that it ever is an issue for Cuttlefish)
and is guaranteed to be available and compatible with the Erlang version the user may want to run Cuttlefish on.

I think it's time for Cuttlefish to drop Lager is it is no longer an essential dependency. Lager's Erlang 24 compatibility, for example, is a developing story that can take a while to perfect (erlang-lager/lager#547).

Cuttlefish's logging needs are fairly basic, so let's use the built-in thing.