Deprecation messages with Erlang/OTP 20 - Elixir 1.5.3

[KrisLamote]

Hello,
While compiling a project with a mariaex dependancy I get some deprecated messages for mariaex. The original project is (still) running with: Erlang/OTP 19 and Elixir 1.4
In order to get things upgraded I bumped my stack to: Erlang/OTP 20 and Elixir 1.5.3. Withh these versions I get:

mix deps.get
...
mariaex 0.8.4
...
* Getting mariaex (Hex package)
...

mix deps.compile
...

==> mariaex
Compiling 14 files (.ex)
warning: String.strip/2 is deprecated, use String.trim/2 with a binary second argument
  lib/mariaex/messages.ex:285

warning: String.to_char_list/1 is deprecated, use String.to_charlist/1
  lib/mariaex/protocol.ex:138

warning: Kernel.to_char_list/1 is deprecated, use Kernel.to_charlist/1
  lib/mariaex/protocol.ex:1034

...

There is more - but unrelated to mariaex.

It this intentionally retained for backwards compatibility, or is it just not very important.
In case of the latter - maybe I can have a go..?

Cheers,
Kris

PS.: Thanks for this wonderful package!