Create footer

[gsambrotta]

Implement footer html and style based on mockup:

Footer is shared template between all the pages We don't want footer to be too full of elements Footer must include link to:

• Imprint
• Contact

And:

• OTS logo
• Social links/buttons
• this sentence: "Except where otherwise noted, content on this site is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License. "