Added Google Style Docstrings to core.py file methods (#1161)
Added Google Style Docstrings to core.py file methods (#1161)

* added docstrings to core.py file methods

* minor changes to code formatting according to standards

* Files changed automatically by black for code linting

* linting corrections: removed whitespaces

* changed pre-commit configuration to 3.6

* changed variable name 'message' to 'event'

* Revert "changed variable name 'message' to 'event'"

This reverts commit dcc53023c32065613f7fa18816815036d3b8dc70.

* changed variable name 'message' to 'event'

* changed pre-commit configuration to 3.6

opsdroid/opsdroid,jacobtomlinson/opsdroid,FabioRosado/opsdroid