Fix broken specs in developement environment (#557)

* Fix broken specs in development environment

Author: dougpetronilio

split.gemspec

@@ -41,4 +41,5 @@ Gem::Specification.new do |s|
   s.add_development_dependency 'rspec',       '~> 3.7'
   s.add_development_dependency 'pry',         '~> 0.10'
   s.add_development_dependency 'fakeredis',   '~> 0.7'
+  s.add_development_dependency 'rails',       '>= 4.2'
 end