Simplify feature toggle annotations

See https://github.com/edx/code-annotations/blob/master/CHANGELOG.rst#070---2020-09-07

Multi-line annotation improvement

See https://github.com/edx/code-annotations/blob/master/CHANGELOG.rst#060---2020-08-27

Support for warnings in the `featuretoggles` Sphinx extension

https://github.com/edx/code-annotations/blob/master/CHANGELOG.rst#051---2020-08-25

Add config_and_tools and featuretoggles Sphinx extension

See https://github.com/edx/code-annotations/blob/master/CHANGELOG.rst#050---2020-08-06

Add support for multi-line code annotations

Added support for multi-line code annotations.

Django and Python support updated

• Removed Support for python2.7 and python3.6.
• Removed support for Django<2.2.
• Added support for Python3.8.

v0.3.3

Compatibility with django 2.

v0.3.2

Add RST anchors to each annotation group in generated reports.

v0.3.1

Bump several dependencies, notably pyyaml to 5.1

v0.3

• Adds the ability to generate human readable reports in RST from code-annotations generated YAML files