Removed backup and swap settings, vim-twig plugin; added vim-blade plugin

Codekit isn't compatible with Vim backup and swap files, used it with
them disabled for a few weeks and everything seems OK. Removed the
backup and swap config and replaced it with nobackup, nowritebackup,
and noswapfile

Also removed the vim-twig plugin since I haven't been using Twig for
templating, added vim-blade as a replacement.