issue27202 - Fix the mistake in changesets 70af472451cb (3.5) and 2bb806539ca6 (3.6)

exclude_patterns in Sphinx conf.py will exclude the .rsts from the build. It
was incorrect exclude 2.x rsts in that.  This fix contributed again Jelle
Zijlstra, excludes doctests in whatsnew/2.7.rst from being exercised by using
doctests skip option.
diff --git a/Doc/conf.py b/Doc/conf.py
index 114f9b6..d6f20ba 100644
--- a/Doc/conf.py
+++ b/Doc/conf.py
@@ -36,9 +36,8 @@
 # Require Sphinx 1.2 for build.
 needs_sphinx = '1.2'
 
-# Ignore any .rst files in the venv/ directory, and don't attempt to run tests
-# in the 2.x release notes.
-exclude_patterns = ['venv/*', 'whatsnew/2.*.rst']
+# Ignore any .rst files in the venv/ directory.
+exclude_patterns = ['venv/*']
 
 
 # Options for HTML output