During this upgrade process, `rails server` hasn't been updating its logic when files changed, so every change had to be accompanied by a restart.
This turned out to be because Vagrant's networked filesystem to share between the host and guest systems doesn't support the filesystem update events Rails is listening for. So, we switch to a simpler file watcher that does more work but doesn't depend on the filesystem events!
NOTE: This doesn't boot yet! There's something changed in the `devise` API that we'll need to fix!
```
/vagrant/config/initializers/devise.rb:46:in `block in <top (required)>': undefined method `encryptor=' for Devise:Module (NoMethodError)
```
But yeah, we navigated the gem upgrades, and also I ran `rake rails:update` and hand-processed the suggestions it had for our config files.
