      "        assert_equal(stack.peek(), 5)\n",
      "        assert_equal(stack.min(), 5)\n",
      "        stack.push(1)\n",
      "        assert_equal(stack.peek(), 1)\n",
      "        assert_equal(stack.min(), 1)\n",
      "        stack.push(3)\n",
      "        assert_equal(stack.peek(), 3)\n",
      "        assert_equal(stack.min(), 1)\n",
      "        stack.push(0)\n",
      "        assert_equal(stack.peek(), 0)\n",
 
</s>
    "        assert_equal(stack.minimum(), 1)\n",
      "        assert_equal(stack.peek(), 5)\n",
      "        assert_equal(stack.min(), 5)\n",
      "        stack.push(1)\n",
      "        assert_equal(stack.peek(), 1)\n",
    "        assert_equal(stack.minimum(), 1)\n",
      "        stack.push(3)\n",
      "        assert_equal(stack.peek(), 3)\n",
      "        assert_equal(stack.min(), 1)\n",
      "        stack.push(0)\n",
      "        assert_equal(stack.peek(), 0)\n",
keep keep keep keep replace keep keep keep keep keep
 Update stack min challenge (#128)

Rename variable min_vals to stack_of_mins to improve clarity.
Rename method min to minimum to avoid using the same name as the built-in min.
stacks_queues/stack_min/stack_min_solution.ipynb