Add static landing page

Todo:
- tooltips
- Login form
Use opentip for sign-up form tooltips
Add login via meducation account button
Adding link and facebook auth hrefs
Add login modal using PicoModal library
Add login modal using PicoModal library
Merge branch 'landing-page' of github.com:meducation/design_staging_app into landing-page
Merge pull request #7 from meducation/landing-page

Static landing page