patient-doctor relationship created-now to implement save of build within email background worker
send email invite : next put the email creation into a backgroun worker : then set up the custom routes and actions to create a doctor's account or sign-in as an existing doctor and create the association to the patient
Healthcare table replaced the wrong implementation of the HABTM table
association between doctors and patients created on email sign-up - needs better test coverage
added views and routes for patient::doctor & doctor::patient list and show