Drop support for Elixir lower than 0.12.2
Drop support for Elixir lower than 0.12.2

[ci skip]

waffleio/poxa,edgurgel/poxa,theinventor/rs-poxa,RobertoSchneiders/poxa,waffleio/poxa,joshk/poxa,joshk/poxa,edgurgel/poxa,edgurgel/poxa,RobertoSchneiders/poxa