Add a missing trailing dot to the Name of ResourceRecordSet

AWS Route53 treats www.example.com (without a trailing dot)
and www.example.com. (with a trailing dot) as identical.
Hence, after creating a `www.example.com` record,
`www.example.com.` name is saved in Route53.
But moto treated `www.example.com` and `www.example.com.` as different.

This commit fixes the moto behavior.

moto/route53/responses.py

@@ -123,6 +123,9 @@ class Route53(BaseResponse):
                     """ % (record_set['Name'], the_zone.name)
                     return 400, headers, error_msg
 
+                if not record_set['Name'].endswith('.'):
+                    record_set['Name'] += '.'
+
                 if action in ('CREATE', 'UPSERT'):
                     if 'ResourceRecords' in record_set:
                         resource_records = list(