Fix a plural mistake REVIEWING.rst
Reviewing the REVIEWING.rst of tempest,
I noticed a plural mistake.
The word "APIs" is plural and it shouldn't add 'a' in the front.
And there is an extra "that" before "which".
So I fix it.
Change-Id: I84d81f44314feadaebfcd4a834f854364328593b
diff --git a/REVIEWING.rst b/REVIEWING.rst
index 766d0c6..a880181 100644
--- a/REVIEWING.rst
+++ b/REVIEWING.rst
@@ -42,8 +42,8 @@
API Stability
-------------
-Tests should only be added for a published stable APIs. If a patch contains
-tests for an API which hasn't been marked as stable or for an API that which
+Tests should only be added for published stable APIs. If a patch contains
+tests for an API which hasn't been marked as stable or for an API which
doesn't conform to the `API stability guidelines
<https://wiki.openstack.org/wiki/Governance/Approved/APIStability>`_ then it
should not be approved.