assert_abs_diff_eq does not allow specifying epsilon

Why can't I specify custom epsilon with `assert_abs_diff_eq` but I can with `abs_diff_eq`

```rust
// not possible
assert_abs_diff_eq!(1.0, 1.0, epsilon = f64::EPSILON);

// possible
abs_diff_eq!(1.0, 1.0, epsilon = f64::EPSILON);
```

This makes me unable to write write Rust tests so that I can see the `left` and `right` values on test errors when setting epsilon is needed.