Rewrite specs using new rspec syntax

This pull request uses the `transpec` gem to rewrite all of the spec files to use the new rspec syntax.

Instead of 
```ruby
:foo.should eq(:bar)
```
This would be written as
```ruby
expect(:foo).to eq(:bar)
```

This seemed like a fairly arduous task to do by hand, so I'm pretty stoked that someone wrote a gem that does it automagically.