require a more recent version of rspec

* 2.99 deprecates everything that is removed in 3.0
use transpec to update our spec syntax
these specs should check for an actual true object
upgrade rspec to 3.0
File.exists? is deprecated
refactor this method to avoid a ruby warning on 2.1

* warning: unknown unpack directive '*' in 'H2*'
avoid shadowing a variable
remove variable a ssignment that isn't used
avoid using an instance variable that doesn't exist
this reads a little nicer
use eq() intsead of eql() in specs

* we want to check the results with ==, not ===
this reads a bit better too
Merge pull request #5 from conversation/update-rspec

Update rspec to 3.0