Convert to 2 space indentation.  See: https://github.com/bbatsov/ruby-style-guide
Convert comments to rdoc.
Move code around to stop using public/private unecessarily.

Public marks all methods after it as public.  Private does the same.
Initially, methods are public, so I've reduced this to just one use of
"private"
Change send to send_email.

Ruby uses the send method for message passing.  That is, calling a
method on an object uses the send method to send it a message.  Using
your own send message can break things in weird ways.  While end users
can get around your use of send, it's more conventional to not define a
method simply as send.

See: http://ruby-doc.org/core-1.9.3/Object.html#method-i-send
Remove debug code.
Allow a base URL to be based in, instead of specifying all of its parts piecewise.
Improve api_request method.

- request_path just returns a path and not an entire URL
- HTTPS support will just work when URLS get it
- catch some standard HTTP errors

Ideally, errors should be wrapped into their own error classes.
Tweak comments.