Adds last week and today parameters

Hi there! Thanks so much for creating this script and making it freely available! I've been using it a ton.

I added a things I was wishing for personally, and thought you might be interested in pulling them into the project. I hope you like them!

- I added the -t option to show only todays events
- I added the --lw option to show last week events
- I changed the days in a week to be 7 instead of 6
- I removed unnecessary whitespace I was receiving warnings about