v0.1.0

Added

• vmt start <name> [+tags] to begin tracking a work session, with an optional
  --at flag to backdate the start time.
• vmt status to show the currently tracked session and elapsed time.
• vmt stop to end the active session, with --at and --round flags to adjust
  the exact end time
• vmt log to display sessions tracked over the last 7 days.
• Session tags (e.g. +python) for categorizing tracked work.