Solves #354
Add simple MQTT support to subscribe to, publish messages.
Tweak wording
Assume the payload is going to be JSON
Indent description
Add presence validation
Add db migration
Made expected_update_period_in_days an option
Default the update period if not set
Remove requirement for expected_update_period_in_days (since we default it if it doesn't exist)
Add fake MQTT server from ruby-mqtt gem
Introduce a max_read_time
Add initial specs
Make specs pass
Mixed whitespace :(
Update to cast to int
Dead code
Pick a higher port
Add to_i
Fix migration to actually do the right thing