Relax the version constraints of dependencies

Author: mrkn

pycall.gemspec

@@ -30,11 +30,11 @@ Gem::Specification.new do |spec|
   spec.require_paths = ["lib"]
   spec.extensions    = ["ext/pycall/extconf.rb"]
 
-  spec.add_development_dependency "bundler", "~> 1.13"
-  spec.add_development_dependency "rake", "~> 10.0"
+  spec.add_development_dependency "bundler", ">= 1.17.2"
+  spec.add_development_dependency "rake"
   spec.add_development_dependency "rake-compiler"
   spec.add_development_dependency "rake-compiler-dock"
-  spec.add_development_dependency "rspec", "~> 3.0"
+  spec.add_development_dependency "rspec"
   spec.add_development_dependency "launchy"
   spec.add_development_dependency "pry"
   spec.add_development_dependency "pry-byebug"