Version 0.2

This is a major update that restructures config slightly - see the new README for an example. (Semver will start at v1, I think.)

Changes:

• Drivers and rules are now pluggable! Create your own rule or driver file similar to the ones available in the rules/ and drivers/ folder, save it, and then call it by its filename in your config.yml. This will enable easy (albeit somewhat more difficult to share) custom rules. In the future, I hope to refine this system.
• Fixed a bug preventing initial sign-in, and improved some of the driver code to make the OTP section of the sign-in more consistent.