Add accounts

Teaching notes:

> meteor add accounts-password
> meteor add accounts-ui
Add {{> loginButtons}}
Remove insecure and add policy
Teaching notes:

Add {{#if currentUser}} around form and delete button
> meteor remove insecure
Try to remove
Add userId to pomodoro
Only find pomodoros for current user
Add allow rules
NOTE: we're still publishing all Pomodoros
Make tests pass
Remove autopublish, add explicit publish/subscribe

Teaching notes:

Obviously don't always want all data mirrored on client for performance and security reasons

> meteor remove autopublish
Add publish on server
Add subscribe on client
NOTE: we're still publishing all pomodoros