Update RedditKit's dependencies to use >= rather than ~>.

lib/redditkit/client/users.rb

@@ -87,8 +87,6 @@ def unfriend(user)
       def username_available?(username)
         response = get('api/username_available.json', :user => username)
         available = response[:body]
-
-        available == 'true'
       end
 
       # Registers a new reddit account. 

lib/redditkit/response/parse_json.rb

@@ -1,5 +1,5 @@
 require 'faraday'
-require 'json'
+require 'multi_json'
 
 module RedditKit
 
@@ -13,8 +13,8 @@ class ParseJSON < Faraday::Response::Middleware
       #   an application/json header, we want to return the body itself if the
       #   JSON parsing fails, because the response is still likely useful.
       def parse(body)
-        JSON.parse(body, :symbolize_names => true) unless body.nil?
-      rescue JSON::ParserError
+        MultiJson.load(body, :symbolize_keys => true) unless body.nil?
+      rescue MultiJson::LoadError
         body
       end
 

redditkit.gemspec

@@ -20,7 +20,9 @@ Gem::Specification.new do |spec|
   spec.test_files    = spec.files.grep(%r{^(test|spec|features)/})
   spec.require_paths = ["lib"]
 
-  spec.add_dependency 'faraday', "~> 0.8"
-  spec.add_dependency 'htmlentities', "~> 4.3"
+  spec.add_dependency 'faraday', ">= 0.8"
+  spec.add_dependency 'htmlentities', ">= 4.3"
+  spec.add_dependency 'multi_json', '>= 1.8'
+
   spec.add_development_dependency 'dotenv'
 end