Version bump to 0.21.0.pre
Updated to contour 2.2.0.beta2 and pg 0.17.0
Remove sign in notice on root path
Remove fade in effect from modals
Inline checkboxes now wrap text correctly on smaller screens
Fixed control size dropdown not activating when adding new variables to an existing grid variable
Dropdowns in multi row grids now keep correct width, closes #36.
Removed unused control size for grid variables
The project page has been reorganized to highlight three steps, closes #37.
Make data collection a link if data exists
Small fix to styling of exports on project page
Schedules added to allow grouping of designs that can be assigned to subjects
Editing autocomplete variables now display user submitted variables for reference, closes #41.
Adding sections and variables is now more apparent on design editor, closes #39.
Some cleanup, and only show user submitted values if some exist
Recent activity now displays a message if there hasn't been any recent activity, closes #38.
Schedules added to allow subjects to be assigned groups of designs by date, addresses part of issue #42

- Schedules allow subjects to be assigned groups of designs by date
- Schedules are comprised of multiple events
    - Each event is specified with a date offset
    - Each event can contain one or more designs
    - An event can only be included once per schedule
    - A design can only be included once per event
Fixed a bug in saving the subject_schedule intitial_due_date
Formatting
Prototyping loading events and schedules into sheets, addresses #42.