dependencies updated

Author: doersf

block_io.gemspec

@@ -19,8 +19,8 @@ Gem::Specification.new do |spec|
   spec.require_paths = ["lib"]
 
   spec.add_development_dependency "bundler", "~> 1.6"
-  spec.add_development_dependency "httpclient", "~> 2.4"
-  spec.add_development_dependency "json", "~> 1.8"
-  spec.add_development_dependency "connection_pool", "~> 2.0"
+  spec.add_development_dependency "httpclient", "~> 2.4", '>= 2.4.0'
+  spec.add_development_dependency "json", "~> 1.8", '>= 1.8.1'
+  spec.add_development_dependency "connection_pool", "~> 2.0", '>= 2.0.0'
   spec.add_development_dependency "rake", "~> 0"
 end