   append new compilers to Mix:
 
       def project do
-        [compilers: Mix.compilers ++ [:foo, :bar]]
+        [compilers: Mix.compilers() ++ [:foo, :bar]]
       end
 
   """

  Aliases may also be lists, specifying multiple tasks to be run
  consecutively:

      [all: [&hello/1, "deps.get --only #{Mix.env}", "compile"]]

  In the example above, we have defined an alias named `mix all`,
  that prints hello, then fetches dependencies specific to the

        use Mix.Task

        def run(_) do
          Mix.shell().info("hello")
        end
      end

