iter-progress 0.8.0

Calculate progress of your iterators
Documentation
## v0.8.0 (2021-04-24)

* New functionality: `OptionalProgress` for when generating a timestamp every iteration might be a performance hit.
* Internal refactoring to speed up unit tests

## v0.7.0 (2020-06-12)

* State gets `.assume_fraction(…)` for when you want to force a specific fraction value

## v0.6.0 (2020-01-02)

* Replace `.recent_rate()` with exponential & rolling average functionality
* Remove `.message()`, please write your own message
* Added `.assume_total(usize)` functionality, allowing you to use this total as final fall back
* Use `f64` instead of `f32` in some place (e.g. `.fraction()`)
* Added `.eta()` & `.estimated_total_time()` methods to retrieve that when the
  total is estimatable.
* Minor internal code clean ups

## v0.5.0 (2019-09-28)

* Change licence to [Affero GPL licence]LICENCE
* Minor documentation improvements

## v0.4.0 (2017-02-10)

### Features

* Add `.into_inner()` to get the inner iter back out ([940a4626]940a4626)


## v0.2.0 (2016-04-11)

### Features

* Add `should_print_every_sec` method ([fd554c55]fd554c55)
* ProgressRecords now keep track of when iteration started ([9e7fb771]9e7fb771)
* Keep track of previous timestamp of records ([bb2208f6]bb2208f6)
* Keep track of recent rate, rather than global rate ([46e43adb]46e43adb)


##  (2016-03-08)

### Features

* Accept any Display-able thing for a message ([68104ea2]68104ea2)
* Improve default message ([f08198d4]f08198d4)
* Add `.fraction()` method which tells you how far you are along ([fa799e50]fa799e50)
* Add print_every method ([7741193d]7741193d)
* Add simple time tracking ([8e8d5ad4]8e8d5ad4)