Appointments featurettes

For this feature, I created views for appointments and a controller that will allow any CheckMark user to create, edit, and remove their appointments. In addition, each CheckMark user is able to share/invite more than one of their CheckMark friends. To do this, a CheckMark user simply needs their friend's email who is in the CheckMark system to be sent over otherwise it will be rejected. (The reason I didn't list all the emails in the form is because I don't want users to know other people's emails for privacy reasons.) All CheckMark users is also allowed to accept or decline a invited appointment that will be used later on for the next feature (email, sms, calls). I also created very simple styles for every view.