Improve error

lib/whaleback/errors.rb

 module Whaleback
+  class Error < StandardError
+  end
+
   module Errors
+    class BaseError < Whaleback::Error
+      attr_accessor :message, :code, :status
+      def initialize message, code, status
+        super(message)
+        @message, @code, @status = message, code, status.to_i
+      end
+    end
   end
 end
\ No newline at end of file

lib/whaleback/errors/base_error.rb

-module Whaleback
-  module Errors
-    class BaseError < RuntimeError
-      attr_accessor :message, :code, :status
-      def initialize message, code, status
-        super(message)
-        @message, @code, @status = message, code, status.to_i
-      end
-    end
-  end
-end