anchor.diff:  rerunning in a splitscreen with vim every time I save a file. The constant
   feedback means I don't need to keep switching mental context to see if my code
   is correct: I can, while still in my editor, just glance over at a current test
  -run. If I have to go to a bunch of extra work just to eat my vegetables, I'll
  -eat fewer of them. This has utterly revolutionized how I feel about
  -refactoring: knowing exactly when my code breaks and unbreaks as I rearrange
  -things is a massive help for refactoring, and reveals bugs pretty much the
  -instant they are introduced. I haven't had to write a `debugger` in anger in a
  -shockingly long time. I want that confidence and speed in rails, too.
  +run. This has utterly revolutionized how I feel about refactoring: knowing
  +exactly when my code breaks and unbreaks as I rearrange things is a massive
  +help for refactoring, and reveals bugs pretty much the instant they are
  +introduced. I haven't had to write a `debugger` in anger in a shockingly long
  +time. I want that confidence and speed when I work on rails projects, too.
   
   So, to recap, I want
   
  
positive.code: 
  Now just fire up `guard` with the command `guard`. Shazam! Your tests will run on save.
  
  The little prompt `guard` gives you is an interactive ruby console (whether
  `pry` or `irb` depends on your `Gemfile`, I believe), too. So considerate. Use
  Ctrl-d to kill it, or just close your terminal.
  
negative.code: spring rspec  0.27s user 0.08s system 25% cpu 1.398 total
  ```
  
  Either way, `spring` made the tests *much* faster after the first run, and
  those savings persist so long as the spring server is running.
  
  <%= section 'Setup Guard' %>
  
  