draft implementation of auto import of pyexcel-xls

pyexcel_xls/__init__.py

@@ -10,6 +10,9 @@
 from pyexcel_io.io import get_data as read_data, isstream, store_data as write_data
 
 
+__pyexcel_io_plugins__ = ['xls']
+
+
 def get_data(afile, file_type=None, **keywords):
     if isstream(afile) and file_type is None:
         file_type = 'xls'