test.support.open_urlresource should work from an installed Python

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2016-09-07.16:59:06.272>
labels = ['type-bug']
title = 'test.support.open_urlresource should work from an installed Python'
updated_at = <Date 2016-09-07.16:59:06.272>
user = 'https://github.com/zware'

bugs.python.org fields:

activity = <Date 2016-09-07.16:59:06.272>
actor = 'zach.ware'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = []
creation = <Date 2016-09-07.16:59:06.272>
creator = 'zach.ware'
dependencies = []
files = []
hgrepos = []
issue_num = 28001
keywords = []
message_count = None
messages = []
nosy_count = 3.0
nosy_names = ['christian.heimes', 'r.david.murray', 'zach.ware']
pr_nums = []
priority = 'normal'
resolution = None
stage = 'needs patch'
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue28001'
versions = ['Python 2.7', 'Python 3.5', 'Python 3.6']