Relax bundler dependency to make it easier to get started contributing

It fixes #8

Author: etagwerker

rails_stats.gemspec

@@ -19,5 +19,5 @@ Gem::Specification.new do |spec|
   spec.require_paths = ["lib"]
 
   spec.add_dependency "rake"
-  spec.add_development_dependency "bundler", "~> 1.6"
+  spec.add_development_dependency "bundler", ">= 1.6", "< 3.0"
 end