Phase 4 - users and sessions
users own cats and rental requests
Add multiple logins
Refactoring, minor CSS changes
Add 'week4/day3/3_cats/' from commit '609ddbb3036ef6067257668558200cef4c972d51'

git-subtree-dir: week4/day3/3_cats
git-subtree-mainline: d3fdb4b344e4bee73101a51318f471acb9e9d7ad
git-subtree-split: 609ddbb3036ef6067257668558200cef4c972d51
partner attribution