Prepare 17.0.0 (#617)

diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index e5e01c6..414dac3 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -5,7 +5,7 @@
 The third digit is only for regressions.
 
 
-17.0.0 (UNRELEASED)
+17.0.0 (2017-04-20)
 -------------------
 
 Backward-incompatible changes: