[Add] alias, import and use module attrs

Author: kmlroot

alias.exs

@@ -0,0 +1,3 @@
+defmodule Stats do
+  alias Math.List, as: List
+end

struct.exs

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+defmodule User do
+  defstruct name: "Mauricio", age: 22
+end

use.exs

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+defmodule AssertionTest do
+  use ExUnit.Case, async: true
+
+  test "always pass" do
+    assert true
+
+  end
+end