adapt pyexcel 0.3.0 meta class introduction

Author: chfw

pyexcel_text/_json.py

@@ -60,6 +60,3 @@ def _serializer(obj):
     elif isinstance(obj, datetime.date):
         return obj.strftime('%Y-%m-%d')
     return str(obj)
-
-
-renderers = (Jsonifier,)

pyexcel_text/_text.py

@@ -52,6 +52,3 @@ def tabulating(sheet, file_type, write_title):
         tablefmt=file_type,
         **keywords)
     return content
-
-
-renderers = (Tabulater,)