Can't set `className` on TableCell

[bartaz]

Even that TableCell seems to have className prop defined it's not set on rendered element in static table.

<Table>
	<TableRow tableHeading>
		<TableCell className="test">Test heading</TableCell>
    </TableRow>
	<TableRow>
		<TableCell className="test">Test data</TableCell>
    </TableRow>
</Table>

It makes it impossible to change width of table columns. TableCell doesn't accept the width attribute, and className that could possibly be used to add width via CSS does not work.

Expected

Adding className to TableCell should work as documented and there should be the way to change the widths of the columns.