Cleaned up date parsing.

Also react with 👍 regardless of is verbose is true so it's more clear to people what to react to in order to subscribe

try dateutils.parse before searching, works better when the date string is at the beginning of the message.

Also improved date formatting

Initial commit

Allow one-digit hour for german time

E.g. !reminder morgen um 8:30
instead of !reminder morgen um 08:30

Closes #14

Also removed unused regexes