Update doc version to 4.0
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@289206 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/conf.py b/docs/conf.py
index e385406..cd793dd 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -47,9 +47,9 @@
# built documents.
#
# The short X.Y version.
-version = '3.9'
+version = '4.0'
# The full version, including alpha/beta/rc tags.
-release = '3.9'
+release = '4.0'
# The language for content autogenerated by Sphinx. Refer to documentation
# for a list of supported languages.