Feature request: Create a wrapper to assign a layer to several calls

[lagartoverde]

Currently you can only add a layer to a call manually and one by one like

match "/assets/*path", %{ layer: :static } do
  forward conn, path, "http://frontend/assets/"
end

get "/index.html", %{ layer: :static } do
  forward conn, [], "http://frontend/index.html"
end

We are aiming to allow the following syntax

in_layer :static do

  match "/assets/*path" do
    forward conn, path, "http://frontend/assets/"
  end

  get "/index.html" do
    forward conn, [], "http://frontend/index.html"
  end

end

Resulting in less repetition and a much cleaner code