update to elixir-1.3

[0xAX]

Warning fixes which are occured in elixir-1.3.

Ecto is not updated. Updated dependencies are only need for otp-19 and elixir-1.3

[coveralls]

Coverage remained the same at 62.945% when pulling 1fd6c7c on 0xAX:elixir-1-3 into 0355750 on xerions:master.

[coveralls]

Coverage increased (+0.9%) to 63.814% when pulling e5c0e84 on 0xAX:elixir-1-3 into 0355750 on xerions:master.

[coveralls]

Coverage increased (+0.9%) to 63.814% when pulling 243fb13 on 0xAX:elixir-1-3 into 0355750 on xerions:master.