Reverse method on event readers.

Related to #87.
*Pseudocode*
```c#
var sut = FifoEvents<T>(a, b, c);
var expected = LifoEvents<T>(a, b, c);

var actual = sut.Reverse();

// -> Verify that the expected sequence equals the actual sequence.
// -> Verify that actual instance equals expected instance via Structural Equality. 
```