v0.8.0-alpha.0 -- MVP alpha release!

This (pre-)release focuses on authentication and authorization, and includes a fully-functional RBAC implementation for bundle commands. We consider this to be the "killer feature" for Gort, and we're very excited for its completion.

With this release, Gort is now considered to be minimally feature complete. There will be bugs, of course. There will be rough spots. Lots of them. But as of this (pre-)release you could theoretically set up and execute a complete ChatOps solution with RBAC.

Changes include:

1. Roles and permissions. Roles group one or more permissions, and can be granted to groups. Groups are groups of users. Includes the addition of the gort role CLI subcommands.
2. Command rules and permissions. Permissions and execution rules are fully implemented. This is a major feature. See the Gort Guide for more details.
3. Default Gort Bundle. When first bootstrapped, a Gort deployment receives a default gort bundle for basic administration. It includes several rules that restrict execution to the administrator (and anybody who may get the appropriate permissions in the future).
4. Addition of RBAC to REST API. The REST API now performs user authentication and authorization by comparing the given function against the rules defined in the default Gort bundle. So, if you can execute the default Gort command, you can execute the same function via the API.