Add Run ExUnit Tests In A Deterministic Order as an elixir til

elixir/run-exunit-tests-in-a-deterministic-order.md

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+# Run ExUnit Tests In A Deterministic Order
+
+When running a file of
+[`ExUnit`](http://elixir-lang.org/docs/stable/ex_unit/ExUnit.html) tests,
+they will be executed in a pseudo-random order based on a seed value. In
+general, `ExUnit` will pick a random seed each time you run your tests. If
+you'd like to add some determinism to the order that your tests run in, you
+can specify the seed in the `ExUnit` configuration.
+
+```elixir
+ExUnit.configure seed: 42
+ExUnit.start
+
+defmodule AssertionTest do
+  use ExUnit.Case, async: true
+
+  test "the truth" do
+    assert true
+  end
+
+  test "more truth" do
+    assert 2 + 2 = 4
+  end
+end
+```
+
+[source](https://til.hashrocket.com/posts/4a7dc5fd94-run-exunit-tests-in-the-order-they-are-defined)
+
+h/t Chris Erin