Py3.6 test_user.py fail re string interpretation

[phillxnet]

Post #2567 in testing branch we have the following test failure regarding expected string type:

buildvm:/opt/rockstor/src/rockstor/storageadmin # poetry run django-admin test -v 2 -p test_user.py
...
test_email_validation (rockstor.storageadmin.tests.test_user.UserTests) ... FAIL
...

======================================================================
FAIL: test_email_validation (rockstor.storageadmin.tests.test_user.UserTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/opt/rockstor/src/rockstor/storageadmin/tests/test_user.py", line 274, in test_email_validation
    response.data[0], "{'email': [u'Enter a valid email address.']}"
AssertionError: "{'email': ['Enter a valid email address.']}" != "{'email': [u'Enter a valid email address.']}"
- {'email': ['Enter a valid email address.']}
+ {'email': [u'Enter a valid email address.']}
?            +

----------------------------------------------------------------------
Ran 8 tests in 1.270s

FAILED (failures=1)

[phillxnet]

The Web-UI surfacing of the tested code related to this issue's test failure:

Attempt to Create a user with a nonsense email address, i.e. "email-not-valid.com"

Houston, we've had a problem.
{'email': ['Enter a valid email address.']}

            Traceback (most recent call last):
  File "/opt/rockstor/src/rockstor/rest_framework_custom/generic_view.py", line 41, in _handle_exception
    yield
  File "/opt/rockstor/src/rockstor/storageadmin/views/user.py", line 221, in post
    suser.full_clean()
  File "/opt/rockstor/.venv/lib/python3.6/site-packages/django/db/models/base.py", line 1250, in full_clean
    raise ValidationError(errors)
django.core.exceptions.ValidationError: {'email': ['Enter a valid email address.']}

This looks to be a more proper presentation than to have our unicode designator.

Ergo we move to modifying the test to remove the explicit unicode'' indicator. Given strings default to this now anyway.

[phillxnet]

Closing as: Fixed by #2584