Appointment feedback

(Fulfills #63 requested by @alexbotsford)

Every `INTERVAL`, run rake task `feedback:send_all_requests` that finds Appointments that ended within the last hour and have not had feedback requests sent. Appointments that fit this criteria will have the following email sent to each user:

![](https://photos-3.dropbox.com/t/0/AADdg_x7VMrgK03RUgCmZ2yFMShxefnsUh9wNlfQK07VXA/12/12686470/png/1024x768/3/1392832800/0/2/Screenshot%202014-02-19%2010.44.54.png/swGTezqBpdU3D-kGscjBas6o065wIcxlHBIWr118Mm0)

When the user follows the link, they are taken to a page to fill out a feedback form:

![](https://photos-4.dropbox.com/t/0/AACQn_wVmZHmsvmMf0LI_5z8_EEGlJQxtOLnTuQG-Sy0IA/12/12686470/png/1024x768/3/1392832800/0/2/Screenshot%202014-02-19%2010.46.30.png/FDqWeVlSzcb6yZ0hRly8U2i3t1Yx4SgLz_0QTJP38X8)

When the feedback form is submitted, an email is sent to the feedback receiver, notifying them that new feedback is available for viewing:

![](https://photos-4.dropbox.com/t/0/AAAdkpWOEeD06upxZlLKLELFDeahL1zCXrh26SoOzucYRA/12/12686470/png/1024x768/3/1392832800/0/2/Screenshot%202014-02-19%2010.45.50.png/Te_nFJBAZmk5SB3I3mStHxJuF6ynJJQvigRjNv1jdqw)

When the feedback receiver follows the link, they can see all the feedback given to them associated with the  given appointment:

![](https://photos-6.dropbox.com/t/0/AACPj8iZJms2aLvuozbRNMqC1u6-6Yq4N15A45Z9F9tK-Q/12/12686470/png/1024x768/3/1392832800/0/2/Screenshot%202014-02-19%2010.46.16.png/0-ijgim1bdAzgXx5Pq85uE2mTpAJJSm5xRsp3IaIerY)