Replace Kernel.to_char_list with Kernel.to_charlist (#109)
Replace Kernel.to_char_list with Kernel.to_charlist (#109)

Fixes warning during build:

```
==> rustler
Compiling 2 files (.erl)
Compiling 6 files (.ex)
warning: Kernel.to_char_list/1 is deprecated, use Kernel.to_charlist/1
  lib/rustler/toml_parser.ex:7
```
hansihe/Rustler