Fix functional tests for py3

Fix various things so the functional tests will work under python3:

- A hashlib.md5() can only be update()d with an encoded string in py3.
- There's no dict.iteritems(), change to dict.items() (which is already
  an iterator).
- Open temp files with 'w+' mode rather than the default 'w+b' (as an
  alternative to encoding all the write and expected-read payloads as
  bytes).
- (This is a weird one) Explicitly raise SkipTest from unittest (rather
  than unittest2, which is where cls.skipException landed). Not sure why
  this is busted, but this moves the ball.

Conflict/issue with raising SkipTest on this branch.

(cherry picked from commit f1d742f32adeb662a3fdf8fa3ef3bc391e71ed81)
(cherry picked from commit b866202f54afddca66a77cd989b082e193a96956)

Includes squash of:
Before writing object data to stdout, re-open it in binary mode

Otherwise, you can hit TypeErrors on Python3.

Closes-Bug: 1775482
(cherry picked from commit 415b48056d9d021e04ec972029040a89a6b13928)

Conflicts:
    openstackclient/tests/functional/identity/v3/common.py

NOTE(melwitt): The conflicts are due to the following changes not in
Queens:

  Id8377363f7a3248b45aeeba21d2acc02684a0305
  I7c44bbb60557378b66c5c43a7ba917f40dc2b633

Change-Id: Ic9b2b47848a600e87a3674289ae7ae8c3e091fee
(cherry picked from commit 47f0277208362a3224f8e587bbdd60dd5aebf846)

1 files changed, 1 insertions, 1 deletions

diff --git a/openstackclient/tests/functional/common/test_help.py b/openstackclient/tests/functional/common/test_help.py
index 7f274099..88f7ddbd 100644
--- a/openstackclient/tests/functional/common/test_help.py
+++ b/openstackclient/tests/functional/common/test_help.py
@@ -80,7 +80,7 @@ class HelpTests(base.TestCase):
         """Check help commands without auth info."""
         # Pop all auth info. os.environ will be changed in loop, so do not
         # replace os.environ.keys() to os.environ
-        for key in os.environ.keys():
+        for key in list(os.environ):
             if key.startswith('OS_'):
                 self.useFixture(fixtures.EnvironmentVariable(key, None))