Ruby, 23 bytes
->a{a.sort_by{|i|~i%2}}
###Barely related: this works on ruby from homebrew 2.5.1p57 (because it's based on a small bug) but only for non-negative integers, 20 bytes
->a{a.sort{|i|i%-2}}
->a{a.sort_by{|i|~i%2}}
###Barely related: this works on ruby from homebrew 2.5.1p57 (because it's based on a small bug) but only for non-negative integers, 20 bytes
->a{a.sort{|i|i%-2}}