Added structured data and byline

Added structured data according to Schema.org and byline
Added structured data for Blog

Added structured data for Blog

- schema.org/Blog
- Changed datetime attribute to only show down to minutes
Changed cover height to be static form fluid

Cover height is now a set em rather than percentages. WIll change in stages depending on window-height. Breakpoints are defined along with the other breakpoints  in style.scss
Merge pull request #27 from reedyn/cover-responsivity

Cover responsivity