Add background_image to showreel and works
Move get_slide_background_css to application_controller
  -Change name to get_background_css
Change showreel and works models to pass tests
Rename slide_box to description_box
Align showreel content
Add background to showreel envelope
Remove built-in classes from _embedded_video partial
Add classes to showreel content for styling
put _embedded_video in shared folder and use in works
Add class envelope to works display
Put works contents into "overlay" class
Add background image to repo