Share event links to social media

[clementine-smart]

As a user, I want to easily share a link to an individual event via twitter or facebook.

Design for the "share" icon and position

• [x] investigate twitter and facebook linking features
• [x] plan how you will implement sharing
• [x] implement a "share" functionality for each event

[Richard-So]

please review if the href provided in the anchor tag is enough or was i meant to specify the absolute url to that particular event?