Delete trailing newline character from pasted text

[alexis-lanoix-sixthfin]

Basically a repost of #140 with added test.

Problem

When copying single empty cell from Google Spreadsheet (or copy some values from Excel), pasting result includes extra empty row.

Solution

Removing trailing new line from pasted text.

I think it could be merged quickly because this is pretty straightforward and kind of a showstopper for using Excel or Google Sheets alongside this library.

Thanks! 😃