Widgetastic.core

* Fixed module index page in the docs (186, 187)
* Removed Tox (185)
* Added copy and paste methods to Browser object (183)
* Fixed the issue when automation cannot click on an element due to another overlapping element (182)
* Added generic OUIA classes (177)
* Visibility optimization (168)
* Reset table tree if table element changes (170)
* Travis has been replaced GH Actions (171)
and other fixes

Workaround for Chrome 78 from quarckster

Fixed ParametrizedViewRequest.child_widget_accessed calling

Travis changes, testrun in container

basic browser window handling

Declutter exception logging

Thanks mfalesni, quarckster, and digitronik !

Dropped support of python 2.7

Handling of shadowDOM in move_to_element

Change exception type and logging level for DoNotReadThisWidget