wrongly analysis of with statement by "target" type

[crackevil]

Steps to reproduce

1. have a context manager class, whose enter returns another object rather than "self"
2. write with statement by that class's constructor
3. pylint will warns "no member" error due to it assume "target" is a context manager class
   instance but in fact it was returned by context's enter method

sample code

class client_log(object):
	def __init__(self, client):
		self.client = client

	def __enter__(self):
		return self.client

	def __exit__(self, exc_type, exc_value, traceback):
		logger.info(self.client.get_log())

with client_log(client) as c:
	return c.foo()    **# pylint assume c is a client_log instance but c is a client instance**

pylint --version output

No config file found, using default configuration
pylint 1.9.4,
astroid 1.6.2
Python 2.7.15 (v2.7.15:ca079a3ea3, Apr 30 2018, 16:30:26) [MSC v.1500 64 bit (AMD64)]