prepping for using a postgreql db for sotring emails.
added storing emails in a postgres database, as well as viewing them in a password protected page
added better handling for database errors. Also, /emails now defaults to page 1 when not specifying a page number
improved the documentation and refactored some code in the mailr and helpers modules.
refactored the /email method to be more concise
started passing the Email model object instead of the data dict for clearer code
switched to lower case service names since it is simpler
use (service) instead of (provider) everywhere for consistency. refactored code for simpler logic
removed some unnecessary imports