Implemented Gunning Fog Index calculation and fixed several package vulnerabilities.
3.4.0
Implemented Flesch reading ease calculation app.
3.3.0
Added implementation of Coleman-Liau calculation in a new app 'wagtailreadinglevelcoleman'.
3.2.0
Added SMOG Index mode. This is presented as a separate app called 'wagtailreadinglevelsmog' and can be used with or without the original 'wagtailreadinglevel'.
3.1.0
Monkeypatch added which enables use with Wagtail 2.0 out of the box