Pytlas

- ✨ Added `additional_lookup` property to `settings.get` which will take precedence over `os.environ`. With this modification, you can now use `settings.get('a key', additional_lookup=r.agent.meta)` in skills to allow agent overriding of global settings
- ✨ Added cli command `pytlas train` and removed the `--dry` flag
- ✨ Added cli command `pytlas parse` and removed the `--parse` arg

🍾 This major version build on top of the existing core to add some exciting features, a brand new CLI and context handling to your skills. I really hope you'll enjoy this one as much as I do!

- ⬆️ Updated snips-nlu to 0.18.0
- ✨ [New documentation](https://pytlas.readthedocs.io)
- ✨ Added support for **contexts** with sub intents
- ✨ Brand new CLI with a tiny skills manager which uses git to fetch skills `pytlas skills --help`
- ✨ Markdown formatting when using `text` such as in `answer`, `ask` and `Card` with a raw version to each in case you only need raw text without formatting
- ✨ Settings handling with config/env
- ✨ Added `require_input` parameter to `agent.done` when your skill has done its work but needs some inputs and the client should keep listening
- ✨ Some enhancements here and there

- ♻️ Unit test refactoring!
- ⬆️ Updated snips-nlu to 0.17.1
- 💥 Agent `parse_intent` has been renamed to `queue_intent`
- ✨ Added meta in `agent.ask` and `agent.answer` to enable more presentation options when a client accept custom properties so you now can call `request.agent.answer('Hi', your_meta_name='I will be pass down to the agent on_answer callback!')`

As a **side effect**, `on_answer` and `on_ask` callbacks now accept `**kwargs` as the last argument.

- ✨ Added `--dry` args to the CLI to launch a dry run
- ✨ Added env variables to agent meta when running the CLI
- 🐛 Fixed a bug with snips cached parsed slots
- 🐛 Fixed a bug with restricted choices when asking
- 🐛 Fix crash when skill folder does not exists

- ✨ Added `Request._d` to localize `datetime` object retrieved from `SlotValue.value_as_date`.

- ✨ Added `PYTLAS_LOAD_LANGUAGES` environment variable to prevent unneeded resources to be loaded. If not set, all skill resources will be loaded for all languages so it may take some unused memory space when you already know for which language(s) you want to use pytlas.
- ✨ Added `SlotValue.value_as_date` method to easily retrieved a parsed `datetime` value for a slot.
- ✨ `Request.agent` is now a proxy used to silent skill return when it was canceled (useful when you're doing async stuff in your skill handler).
- 🐛 Fixed slot value not correctly filled for data ranges.