Airtable-python-wrapper

* Adds escaping formula field references 120

* Added Batch update method

* Fix: [batch delete](https://github.com/gtalarico/airtable-python-wrapper/pull/100)

* **Breaking**: Drop Api config from ENV variable - use `api_key` arg instead
* **Breaking**: Drop Python 2 / IronPython Support
* Feature: On HTTP Errors, Raise Original Exception, but with Helpful Errors added
* Fix: 86 formulas with string values

* Removed: `mirror()` method.
* Feature: Configurable request timeout

* Fixed: Python 2 compatibility issues
* Start CI testing on all supported Python versions
* **Breaking**: Drop implicit support for Python 3.4, officially support 3.7 and 3.8.