Brewfile: Install Node with npm

Ref. https://github.com/Homebrew/homebrew/pull/28075. Closes #362.
bootstrap.sh: Make `rsync` output numbers in a human-readable format

Closes #383.
Merge branch 'master' of https://github.com/mathiasbynens/dotfiles

# By Mathias Bynens (1) and ribmo (1)
# Via Mathias Bynens
* 'master' of https://github.com/mathiasbynens/dotfiles:
  bootstrap.sh: Make `rsync` output numbers in a human-readable format
  Brewfile: Install Node with npm