whoops miss understood. removed.

[Josh Чернов]

Failed to use "poison" (version 3.1.0) because
  arc (version 0.8.0) requires ~> 2.2 or ~> 3.1
  ex_aws (versions 1.1.1 and 1.1.2) requires >= 1.2.0
  phoenix (version 1.2.3) requires ~> 1.5 or ~> 2.0
  mix.exs specifies ~> 3.1