Add omniauth-steam strategy directly into plugin

Add omniauth steam strategy directly into the plugin into the file
omniauth-steam.rb and require by require File.expand_path method.
No more reference to omniauth-steam gem used until sources updated.

omniauth-steam.rb

@@ -0,0 +1,60 @@
+# name: omniauth-steam
+# about: omniauth-steam
+# version: 1.0.3
+# author: Rodrigo Navarro
+
+require 'omniauth-openid'
+require 'multi_json'
+
+module OmniAuth
+  module Strategies
+    class Steam < OmniAuth::Strategies::OpenID
+      args :api_key
+
+      option :api_key, nil
+      option :name, "steam"
+      option :identifier, "http://steamcommunity.com/openid"
+
+      uid { steam_id }
+
+      info do
+        {
+          "nickname" => player["personaname"],
+          "name"     => player["realname"],
+          "location" => [player["loccityid"], player["locstatecode"], player["loccountrycode"]].compact.join(", "),
+          "image"    => player["avatarmedium"],
+          "urls"     => {
+            "Profile" => player["profileurl"],
+            "FriendList" => friend_list_url
+          }
+        }
+      end
+
+      extra do
+        { "raw_info" => player }
+      end
+
+      private
+
+      def raw_info
+        @raw_info ||= options.api_key ? MultiJson.decode(Net::HTTP.get(player_profile_uri)) : {}
+      end
+
+      def player
+        @player ||= raw_info["response"]["players"].first
+      end
+
+      def steam_id
+        openid_response.display_identifier.split("/").last
+      end
+
+      def player_profile_uri
+        URI.parse("http://api.steampowered.com/ISteamUser/GetPlayerSummaries/v0002/?key=#{options.api_key}&steamids=#{steam_id}")
+      end
+
+      def friend_list_url
+        URI.parse("http://api.steampowered.com/ISteamUser/GetFriendList/v0001/?key=#{options.api_key}&steamid=#{steam_id}&relationship=friend")
+      end
+    end
+  end
+end

plugin.rb

@@ -1,9 +1,9 @@
 # name: Steam authentication with Discourse
 # about: Authenticate with Discourse with Steam
-# version: 0.2.0
+# version: 0.3.0
 # author: J. de Faye, Sam Saffron
 
-gem 'omniauth-steam', '1.0.3', git: 'https://github.com/reu/omniauth-steam.git'
+require File.expand_path('../omniauth-steam.rb', __FILE__)
 
 class SteamAuthenticator < ::Auth::Authenticator