Slacker

* Add `channel.replies` method
* Add `chat.postEphemeral` method
* Add `chat.unfurl` method
* Add `apps.permissions` methods
* Add `groups.replies` method
* Add `oauth.token` method

* Add example scripts to show listing items & posting to channels 74
* Add `members_exclude` parameter to the `Channels.list` method 105
* Add `RTM.connect` method 106
* Add `channel` parameter to the `Files.list` method 103
* Add `__str__` method to the `Response` class 107
* Add `thread_ts` parameter for `Chat.post_message` method 101
* Added undocumented `users.admin.invite` method 94
* Make sure empty lists are also JSON encoded 93
* Added `__version__` 108
* Support connection pooling via `requests.Session` 111

- Add `im.replies` method
- Add `users.identity` method

- Fix package classifiers. Closes 87
- Enable `mpim.replies` method
- Add `as_user` argument for `chat.delete` method. Closes 96
- Make `file` argument optional for `files.upload` API. Closes 80
- Make `text` argument optional for `chat.post_message` method. Closes 83

- Add `idpgroups.list` method

- Fix `files.comments.edit` typo