Add function specs to Mix public interface (#8745)
Add function specs to Mix public interface (#8745)


kelvinst/elixir,kelvinst/elixir,lexmag/elixir,kimshrier/elixir,kimshrier/elixir,michalmuskala/elixir,elixir-lang/elixir,lexmag/elixir,ggcampinho/elixir,ggcampinho/elixir,pedrosnk/elixir,joshprice/elixir,pedrosnk/elixir