bump dependencies

Author: callum-oakley

pusher.gemspec

@@ -13,18 +13,18 @@ Gem::Specification.new do |s|
   s.description = %q{Wrapper for Pusher Channels REST api: : https://pusher.com/channels}
   s.license     = "MIT"
 
-  s.add_dependency "multi_json", "~> 1.0"
+  s.add_dependency "multi_json", "~> 1.15"
   s.add_dependency 'pusher-signature', "~> 0.1.8"
-  s.add_dependency "httpclient", "~> 2.7"
+  s.add_dependency "httpclient", "~> 2.8"
   s.add_dependency "jruby-openssl" if defined?(JRUBY_VERSION)
 
-  s.add_development_dependency "rspec", "~> 3.0"
-  s.add_development_dependency "webmock"
-  s.add_development_dependency "em-http-request", "~> 1.1.0"
-  s.add_development_dependency "addressable", "=2.4.0"
-  s.add_development_dependency "rake", "~> 10.4.2"
-  s.add_development_dependency "rack", "~> 1.6.4"
-  s.add_development_dependency "json", "~> 1.8.3"
+  s.add_development_dependency "rspec", "~> 3.9"
+  s.add_development_dependency "webmock", "~> 3.9"
+  s.add_development_dependency "em-http-request", "~> 1.1"
+  s.add_development_dependency "addressable", "~> 2.7"
+  s.add_development_dependency "rake", "~> 13.0"
+  s.add_development_dependency "rack", "~> 2.2"
+  s.add_development_dependency "json", "~> 2.3"
 
   s.files         = `git ls-files`.split("\n")
   s.test_files    = `git ls-files -- {test,spec,features}/*`.split("\n")