Bump openstackdocstheme to 1.30.0

...to pick up many improvements, including the return of table borders.

Change-Id: I8853ce602dfaf9e163b77db7cfa0c9d3f2d3fbd7

doc/requirements.txt

@@ -3,6 +3,6 @@
 # process, which may cause wedges in the gate later.
 sphinx!=1.6.6,!=1.6.7,>=1.6.2,<2.0.0;python_version=='2.7'  # BSD
 sphinx!=1.6.6,!=1.6.7,>=1.6.2;python_version>='3.4' # BSD
-openstackdocstheme>=1.18.1 # Apache-2.0
+openstackdocstheme>=1.30.0 # Apache-2.0
 oslotest>=3.2.0 # Apache-2.0
 reno>=2.5.0 # Apache-2.0

lower-constraints.txt

@@ -57,7 +57,7 @@ munch==2.1.0
 netaddr==0.7.18
 netifaces==0.10.4
 neutron-lib==1.26.0
-openstackdocstheme==1.18.1
+openstackdocstheme==1.30.0
 openstacksdk==0.11.2
 os-client-config==1.28.0
 os-ken==0.3.0