Add timezone options

[ekcom]

Server time cannot be used to schedule reminder times because the server may be in a different time zone. Currently, all reminder times are converted to Central time (frankly, because that is my time zone). Different timezone options should be implemented.

The command could be Hey RBot, change timezone to X and it would check if the timezone is valid and then store in database.
We then need to pull that info and use it in setCronAlarm.js