Properly quote TXT/SPF sample data

(Check TXT/SPF records for RFC1035 sec. 5.1.)

Adds quotes and escape for quotes across the TXT/SPF data sets and tests.

Needed-By: https://review.openstack.org/#/c/555398
Change-Id: I5c8160a1cd4a41c4931ab852d478753bb98f4b7d
Closes-Bug: 1755788
diff --git a/designate_tempest_plugin/tests/base.py b/designate_tempest_plugin/tests/base.py
index e411597..bef19f2 100644
--- a/designate_tempest_plugin/tests/base.py
+++ b/designate_tempest_plugin/tests/base.py
@@ -21,7 +21,7 @@
 CONF = config.CONF
 
 
-class AssertRaisesDns(object):
+class AssertRaisesDns(test.BaseTestCase):
     def __init__(self, test_class, exc, type_, code):
         self.test_class = test_class
         self.exc = exc