Fix warnings

/app/controllers/kracken/sessions_controller.rb:11: warning: assigned but unused variable - current_user
/lib/kracken/config.rb:7: warning: instance variable @provider_url not initialized
/lib/kracken/config.rb:11: warning: instance variable @user_class not initialized
/lib/kracken/controllers/authenticatable.rb:95: warning: instance variable @current_user not initialized

Author: cupakromer

app/controllers/kracken/sessions_controller.rb

@@ -8,7 +8,6 @@ def index
 
     def create
       @user = user_class.find_or_create_from_auth_hash(auth_hash)
-      current_user = @user
       session[:user_id] = @user.id
       session[:user_cache_key] = cookies[:_radius_user_cache_key]
       session[:token_expires_at] = Time.zone.at(auth_hash[:credentials][:expires_at])

lib/kracken/config.rb

@@ -4,11 +4,11 @@ class Config
     attr_writer :provider_url, :user_class
 
     def provider_url
-      @provider_url || PROVIDER_URL
+      @provider_url ||= PROVIDER_URL
     end
 
     def user_class
-      @user_class || ::User
+      @user_class ||= ::User
     end
   end
 end

lib/kracken/controllers/authenticatable.rb

@@ -92,8 +92,7 @@ def current_user=(u)
       end
 
       def current_user
-        return @current_user if @current_user
-        fetch_current_user
+        @current_user ||= fetch_current_user
       end
 
       def fetch_current_user