Update dependencies

Pretty please update so I can use the `github_api` gem in combination with this?  Cheers.

Author: codenamev

bitbucket_rest_api.gemspec

@@ -14,9 +14,9 @@ Gem::Specification.new do |gem|
   gem.files = Dir['Rakefile', '{features,lib,spec}/**/*', 'README*', 'LICENSE*']
   gem.require_paths = %w[ lib ]
 
-  gem.add_dependency 'hashie', '~> 2.1.1'
+  gem.add_dependency 'hashie', '>= 3.2'
   gem.add_dependency 'faraday', '~> 0.9.0'
-  gem.add_dependency 'multi_json', '~> 1.3'
+  gem.add_dependency 'multi_json',  '>= 1.7.5', '< 2.0'
   gem.add_dependency 'faraday_middleware', '~> 0.9.0'
   gem.add_dependency 'nokogiri', '>= 1.5.2'
   gem.add_dependency 'simple_oauth'