[ES] Add spanish translation of mix tasks lesson (#1551)
[ES] Add spanish translation of mix tasks lesson (#1551)


nscyclone/elixir-school,doomspork/elixir_school,doomspork/elixir_school,nscyclone/elixir-school,doomspork/elixir_school,nscyclone/elixir-school,doomspork/elixir-school,doomspork/elixir-school,doomspork/elixir-school,nscyclone/elixir-school