selection property is a List
*Created originally on Bitbucket by [arkan1313](https://bitbucket.org/%7B15b03dd1-865e-438c-9b49-82b66fb5e8df%7D/)*
I just found a problem when trying to get the active_cell parameter.
> MyDataSheet.active_cell
```
#!python
/usr/local/var/pyenv/versions/3.7.0/lib/python3.7/site-packages/openpyxl/worksheet/worksheet.py in active_cell(self)
173 @property
174 def active_cell(self):
--> 175 return self.sheet_view.selection.activeCell
176
177 @property
AttributeError: 'list' object has no attribute 'activeCell'
```
Looking at the code openpyxl/worksheet/worksheet.py, the property functions around lines 170-175 (selected_cell and active_cell) are missing that "selection" is a list
issue