move WikiError into Granblue namespace to fix production autoloading

app/errors/WikiError.rb

@@ -1,18 +0,0 @@
-# frozen_string_literal: true
-
-class WikiError < StandardError
-  def initialize(code: nil, page: nil, message: nil)
-    super
-    @code = code
-    @page = page
-    @message = message
-  end
-
-  def to_hash
-    {
-      message: @message,
-      code: @code,
-      page: @page
-    }
-  end
-end

lib/granblue/wiki_error.rb

@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+
+module Granblue
+  class WikiError < StandardError
+    def initialize(code: nil, page: nil, message: nil)
+      super
+      @code = code
+      @page = page
+      @message = message
+    end
+
+    def to_hash
+      {
+        message: @message,
+        code: @code,
+        page: @page
+      }
+    end
+  end
+end