Jupyter-helpers

No changes in comparison to v0.2.2 - just fixing the readme on PyPI

Bug fixes:
- add expire time to GNOME notifications (it might or might not be respected by your desktop, see [Notify-send ignores timeout?](https://askubuntu.com/questions/110969/notify-send-ignores-timeout))
- add limit for the text length in the notifications as those were freezing my GNOME when an exception with a huge traceback was thrown; use new arguments to the `Notification` class to adjust:
- `max_title_len`: maximal length of the title to show in the notification
- `max_text_len`: maximal length of the text to show in the notification

- added smart scroll (will not scroll to a cell if already visible) for:
- Notifications use `smart_scroll=False` to disable
- `scroll_to_current_cell` (use `smart=False` to disable)
- when scrolling to a cell, the new behaviour is to scroll so that it is centered on the screen rather than placed on the top edge; change `scroll_to` to adjust.
- fixed behaviour when ipywidgets not available
- improved removal of outputs when ipywidgets are available
- modern browser is now required (sound and sound will not work with Internet Explorer and other archaic browsers)

Updated setup to install requirements

Initial release