Minitest `assert_raises` gets 2 backtraces

[JoshCheek]

Minitest wraps the backtrace on this one, so it doesn't get reported by our RSpec formatter.

class MyTest < Minitest::Spec
  def zomg
    wat
  end
  it 'fails an assert_raises' do
    assert_raises RuntimeError do
      zomg
    end
  end
end