Block dnspython3 1.14.0

rthalley/dnspython#209 is causing py3x
tests to fail in designate.

reverting to 1.12.0 fixes the issue.

We had previously blocked 1.13.0 as it had other issues

rthalley/dnspython#153

This leaves dnspython at 1.14.0, which should allow
swift to continue

Related-Bug: #1628280

Change-Id: I2a50c2a71d338b637098925181e983c4ec122cf5

global-requirements.txt

@@ -35,8 +35,8 @@ django_compressor>=2.0  # MIT
 django-floppyforms>=1,<2  # BSD
 django-formtools  # BSD
 django_openstack_auth>=2.4.0  # Apache-2.0
-dnspython>=1.14.0  # http://www.dnspython.org/LICENSE
-dnspython3>=1.12.0;python_version>='3.0'  # http://www.dnspython.org/LICENSE
+dnspython>=1.14.0;python_version=='2.7'  # http://www.dnspython.org/LICENSE
+dnspython3>=1.12.0,!=1.13.0,!=1.14.0;python_version>='3.0'  # http://www.dnspython.org/LICENSE
 dogpile.cache>=0.6.2  # BSD
 dogtag-pki>=10.3.5.1  # LGPLv3+
 elasticsearch>=2.0.0,<=3.0.0 # Apache-2.0

upper-constraints.txt

@@ -110,8 +110,8 @@ django-formtools===1.0
 django-nose===1.4.4
 django-openstack-auth===2.4.0
 django-pyscss===2.0.2
-dnspython===1.14.0
-dnspython3===1.14.0;python_version=='3.4' or python_version=='3.5'
+dnspython===1.14.0;python_version=='2.7'
+dnspython3===1.12.0;python_version=='3.4' or python_version=='3.5'
 doc8===0.7.0
 docker-py===1.7.2
 docutils===0.12