Tqdm

- `keras` module tidy and fixes
+ fix `batch_size=None` (869)
+ add missing `pop('size')`

- trim on `ncols` overflow with ANSI handling (850, 716 <- 690)
- add `notebook.reset()` (864)
- add `keras.TqdmCallback` (867 <- 835)
- documentation updates
+ document newly added features (above)
+ notebook `ncols` percentage/pixels (276)
- test updates
+ test newly added features (above)
+ add CI for `win` and `osx` (841)
+ `py2` threading

- fix `pandas` unhashable func (862 -> 863)
+ add tests

- fix floating point imprecision raising errors (859)
- fix auto gh releases ([travis-ci/dpl914](https://github.com/travis-ci/dpl/issues/914))
- update CONTRIBUTING ([84 (comment)](https://github.com/tqdm/tqdm/issues/84#issuecomment-167516992))

- officially support `float` for `n` and `total` (802)
+ `notebook`: use `FloatProgress` <= `IntProgress` (471, 456)
+ allow imprecision (`n <= total + epsilon`) (849)
- fix unicode bar format arguments (803 -> 851)
- add `contrib` submodule (815)
- add `wrapattr`, `utils.CallbackIOWrapper`, `contrib.DummyTqdmFile` (84 -> 844)
- update tests
- update documentation
- tidy automatic `snap` deployments
- minor doc update (854)

- add `pandas` builtin operations check (843 <- 697)
- avoid unnecessary `dedent` (837)
- remove unneeded bar logic
- misc code tidy
- update documentation
+ document default argument overriding (370)
+ add missing `isatty()` (713)
+ update badges
+ add code of conduct
- update framework
+ clean CI stages
+ update CI default `py3.6` => `py3.7`
+ automate snap releases (686 <- 685)