Combined PR for issues #4, #6, #11

[hissohathair]

Hoping this is useful. Have merged in @shabegom's PR because I needed it locally. Adding fix for issue #6, and suggested solution for issue #11.

• Fixes issue with vault names containing spaces (#4). Thanks to shabegom.
• Accepts "* [ ]" in addition to "- [ ]" as task indicators (#6)
• Set a due date by adding "// YYYY-MM-DD" to end of task (#11)

Some cleanups and dependency updates suggested by npm audit.

[hissohathair]

Er, sorry - this turned into a monster.

[lizard-heart]

All good. Thanks so much for the contributions.