Fix rspec deprecation

[glittershark]

See albertosaurus/power_enum#24

[albertosaurus]

This unfortunately fails in Travis. Please fix and I'll take another look. Thanks!

[glittershark]

Looks like the issue here (and the deprecation issue in the first place) is an Rspec 2 vs 3 thing. I tried upgrading Rspec in this library to 3.x but genspec >= 2.0, which you're using, doesn't support Rspec 3. I checked out genspec and it looks pretty dead (last commit Nov 5 2013), any thoughts about ripping out that dependency entirely?

[albertosaurus]

'genspec' gave me many a problem throughout the ages (I had to fork it at one point), but there's nothing else that lets you test generators. I may need to live off a fork again. Unfortunately, I'm supervising a client through a major rollout right now, so it'll have to wait a week or two.

[glittershark]

I've got some time this weekend, I'll see if I can take a crack at it then.