Add `@spec` for `Keyword.pop/3` and `Keyword.pop_first/3`
Add `@spec` for `Keyword.pop/3` and `Keyword.pop_first/3`

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