[day-01] setup imc calc and route

lib/wabanex_web/controllers/imc_controller.ex

@@ -0,0 +1,20 @@
+defmodule WabanexWeb.IMCController do
+  use WabanexWeb, :controller
+
+  alias Wabanex.IMC
+
+  def index(conn, params) do
+    params
+    |> IMC.calculate()
+    |> handle_response(conn)
+  end
+
+  def handle_response({:ok, result}, conn), do: render_response(conn, :ok, result)
+  def handle_response({:error, result}, conn), do: render_response(conn, :bad_request, result)
+
+  defp render_response(conn, status, result) do
+    conn
+    |> put_status(status)
+    |> json(%{result: result})
+  end
+end