Start cleanup, remove most user stuff, tests run but fail

- bump ruby version
- remove almost all specs
- clean up Gemfile
Upgrade gems
Fix configs and specs, views mostly work
Use Rubinius and Puma
Downgrade bootstrap
Update about
Merge branch 'cleanup'

I don't plan on writing for this blog anymore, so I've removed the ability to
add new entries through the site.  The gem/config updates are preparation for
switching from Heroku.