Why do not support meta data in service.register  #291

I check this functions, And I want to use mata in register,but there is no entrance to use meta.
pls add meta to regiseter or PR??

def register(
self,
name,
service_id=None,
address=None,
port=None,
tags=None,
check=None,
token=None,
# deprecated use check parameter
script=None,
interval=None,
ttl=None,
http=None,
timeout=None,
enable_tag_override=False):