Development dependencies can't be overridden

[jferris]

Adding a development dependency like this:

s.add_development_dependency "rails", ">= 3.0"

And then trying to override it in an appraisal causes this error: "You cannot specify the same gem twice with different version requirements."

We can solve this by parsing the gemspec instead of relying on bundler's gemspec directive, since bundler doesn't support merging.

[jferris]

This seems to be fixed in the latest version of bundler.