relax bundler gem version requirement

Author: korny

Gemfile

@@ -6,7 +6,7 @@ gemspec
 # Add dependencies to develop your gem here.
 # Include everything needed to run rake, tests, features, etc.
 group :development do
-  gem "bundler", "~> 1.0.0"
+  gem "bundler", ">= 1.0.0"
   gem "rake", "~> 0.9.2"
   gem "RedCloth", RUBY_PLATFORM == 'java' ? "= 4.2.7" : ">= 4.0.3"
   gem "term-ansicolor"