Update Custom Commands to leverage ActiveRecord and save commands to a
database. By default, it will use SQLite. Configuration for this (and
potential configuration for PostgreSQL and MySQL) live in
`config/db.yml`. Inculde a Rakefile for handling DB creation and
migrations.
Rakefile: Add Rakefile to handle running the bot, and DB management
Gemfile: Update with new gem dependencies
db/migrate/*: ActiveRecord migrations for Custom Command
custom_commands.rb: Update to leverage ActiveRecord
Leverage the Rakefile to start the bot, removing the binary file. Update
the Dockerfile to also leverage the Rakefile.
Dockerfile: Update to use Rakefile, and install new dependencies
chronicle: Remove unnecessary start file
Refactor the `chronicle_bot` file into `chronicle` and `matrix`
chronicle.rb: General Chronicle setup
matrix.rb: Start a Matrix-specific bot
Update the bot to read configuration from files, instead of either the
environment, or hard-coded values.
config/db.yml: Database configuration
config/bot.yml: General bot configuration
Update the README to reflect the above change with regards to running
the bot either using the Rakefile, or using a Docker container.
