Explicit complaint about old OpenSSL when testing

Running the tests with an old version of OpenSSL
results in many tests breaking without any hints
of the real cause. This handles that explictly,
stopping execution whenever the version is older
than 1.0 and exiting with an informative message.

Co-Authored-By: Rodrigo Duarte Sousa <rodrigods@lsd.ufcg.edu.br>
Closes-Bug: 1225084

Change-Id: I55e151d3fb4ddbe5ee4bf64bfdc597b4da73f6bb
Use oslo.utils and oslo.serialization

Left timeutils and strutils in openstack/common since they are used in
openstack/common/apiclient and memorycache.

Change-Id: Idb5f09c159d907dfba84cd1f7501f650318af7d9
Docstrings should have :returns: everywhere.

Some of the docstrings have ``:return:`` instead of ``:returns:``
keyword. This patch fixes that and make it consistent.

Change-Id: I4321a63798ab9e2abdf0bbd716bf2b995be22ba3
Actually test interactive password prompt

* keystoneclient/tests/v2_0/test_shell.py
(ShellTests.test_user_create_password_prompt): Remove the password
from the calling environment and fake out the check for an
interactive terminal session so that the code which implements
password prompting will actually be exercised.

Change-Id: I46f45553995316c7d006a83897413d57e127e48c
Merge "Use oslo.utils and oslo.serialization"
Merge "Actually test interactive password prompt"
Merge "Explicit complaint about old OpenSSL when testing"