Fixed data source to json

Data source updated

- version bumbed to 1.4

Fixed data source URL

Data Source Url has changed.

Notification feature

This release consists of:

• restyling of options page
• new feature: chrome notification when discharge is over the limit specified in the options.
• new option to enable and disable the notification

1.1.0: Options:

New Feature: setting the discharge limit, which changes the background color of the number.

First release

Basic functions to display the measurements and change the station are there.