Upgrade libraries

[wingyplus]

Here is the mix update logs:

Resolving Hex dependencies...
Dependency resolution completed:
Unchanged:
  bunt 0.2.0
  erlex 0.2.6
  jason 1.2.2
  makeup 1.0.5
  makeup_elixir 0.15.1
  nimble_parsec 1.1.0
  stream_data 0.5.0
Upgraded:
  credo 1.5.1 => 1.5.6
  dialyxir 1.0.0 => 1.1.0
  earmark_parser 1.4.10 => 1.4.13
  ex_doc 0.23.0 => 0.24.2 (minor)
  file_system 0.2.9 => 0.2.10
New:
  makeup_erlang 0.1.1
* Updating dialyxir (Hex package)
* Updating credo (Hex package)
* Updating ex_doc (Hex package)
* Updating earmark_parser (Hex package)
* Getting makeup_erlang (Hex package)
* Updating file_system (Hex package)

[wingyplus]

I've found warning on Elixir 1.9 with OTP 22 CI:

 warning: the result of the expression is ignored (suppress the warning by assigning the expression to the _ variable)
Warning:   lib/protobuf/decoder.ex:103

Not sure what it's.

[britto]

Hi @wingyplus. You can find more about that warning in #158.