Port sigil koans from iamvery/elixir-koans

7705d743ac/about_sigils.exs
h/t @sebastiangeiger

test/koans/sigils_koans_test.exs

@@ -0,0 +1,19 @@
+defmodule SigilsTests do
+  use ExUnit.Case
+  import TestHarness
+
+  test "Sigils" do
+    answers = [
+      "This is a string",
+      ~S("Welcome to the jungle", they said.),
+      true,
+      "1 + 1 = 2",
+      ~S(1 + 1 = #{1+1}),
+      {:multiple, ["Hello", "world"]},
+      {:multiple, ["Hello", "123"]},
+      ~S(#{1+1}),
+    ]
+
+    test_all(Sigils, answers)
+  end
+end