Add _static folder to fix docs build error and make postgresql job non-voting

Change-Id: Ib783f293120e5f4832d0c2a28352f4abd5a1e935
(cherry picked from commit b1a7ed61f3)

.gitignore

@@ -13,7 +13,6 @@ ChangeLog
 cover/*
 dist/*
 doc/build
-doc/source/_static/
 etc/aodh/aodh.conf
 subunit.log
 

.zuul.yaml

@@ -8,13 +8,15 @@
     check:
       jobs:
         - aodh-dsvm-tempest-plugin-mysql
-        - aodh-dsvm-tempest-plugin-postgresql
+        - aodh-dsvm-tempest-plugin-postgresql:
+            voting: false
         - telemetry-dsvm-integration
         - telemetry-tox-py37
     gate:
       jobs:
         - aodh-dsvm-tempest-plugin-mysql
-        - aodh-dsvm-tempest-plugin-postgresql
+        - aodh-dsvm-tempest-plugin-postgresql:
+            voting: false
         - telemetry-dsvm-integration
         - telemetry-tox-py37
     experimental: