Keeping Test Account Credentials

@jtmoulia is already working on this.

Since Jun 9, 2014.

This is a continuation of #4, specifically addressing having credentials for test accounts within the repo. (there goes security through obscurity)

`include/switchboard.hrl` does include real credentials for a test account. I totally agree, it opens up the account for abuse. It is used for live tests, or tests run against the an actual IMAP server. Perhaps it would be cleaner to mock out IMAP, but I believe that would be throwing out the baby with the bathwater: testing against a IMAP server aligns our code with the real IMAP behavior, and notifies us when and how that behavior changes.

There is already a concept of `LIVE_TESTS` vs `TESTS`, where `LIVE_TESTS` are tests which are run against an external resource, like Gmail. I propose that we keep this separation, but remove the default test account. Instead, if the tester wants to run `LIVE_TESTS` he can provide a list of credentials, and the live tests will be run across ALL credentials. It will remove the credentials from the repo (I'll change the account pass), and it'll be very useful for testing features across multiple IMAP providers.