Config-client

**changelog**

- Fix `fail_fast` property set via environment variable. :bug:

**issues resolved**

- [CONFIG_FAIL_FAST=False does not work](https://github.com/amenezes/config-client/issues/26)

**changelog**
- fix `profile`configuration on CF class.
- contribution of atuldalvi 👏

**issue resolved**
- [Cloud Foundry - Space name not used to set profile](https://github.com/amenezes/config-client/issues/25)

**changelog**

- `config-client` now enables the use integrated with [Flask](https://flask.palletsprojects.com/en/1.1.x/) and [AIOHTTP](https://docs.aiohttp.org/en/stable/). All previous methods are supported but for users of this frameworks the use will be more natural.

Documentation with an example of use is available in the links below:
- Flask: https://config-client.amenezes.net/docs/integrations/1.-flask/
- AIOHTTP: https://config-client.amenezes.net/docs/integrations/2.-aiohttp/

**changelog**

- added command line 💻

instalation:

bash
pip install config-client[cli]

usage:

bash
show help
config -h

show help from client subcommand
config client -h

- code refactored
- added tox to simplify local tests on python versions:
- current versions suported: 3.6, 3.7, 3.8 and pypy3
- tests migrated to pytest

**issues resolved**

- [Please allow us to omit the .json extension](https://github.com/amenezes/config-client/issues/18)
- [Local Configuration Support](https://github.com/amenezes/config-client/issues/19)

**changelog**
- Fix the method to append `.json` extension to URL;

**issues resolved**
- [how to use a diff config server in Cloud Foundry?](https://github.com/amenezes/config-client/issues/20)
- resolved by [PR-21](https://github.com/amenezes/config-client/pull/21) merged. (contribution of anishp55)

**changelog**

- initial setup to use [mypy](http://www.mypy-lang.org/);
- config-client now can be used on [Cloud Foundry](https://github.com/amenezes/config-client#cloudfoundry-integration);
- Now to create singleton class use [`create_config_client`](https://github.com/amenezes/config-client#create-singleton-instance) method.

**issues resolved**

- [Cloud Foundry integration](https://github.com/amenezes/config-client/issues/15)