Calendar widgets and dynamic group creation oh my!

# Changes

### index.html 
* added additional class names to the create-group template inputs. 
* removed the organization field input as this is the same based on logged in user
* added pickadate.js to scripts

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### create-group-view.js 
* added new focus and click events for the date input fields
* added new functions using pickadate.js to dynamically grey out unavailable dates
* selected dates are parsed on the backend by moment.js
* updated organization name set on group to be static based on the current logged in user, rather than making it an input field

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### main.scss
* pickadate.js based css for styling the calendar widget - it's lengthy, but valuable and non-conflicting

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### bower.json
* pickadate.js added as dependency