Start new release cycle (#654)

diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index dc3d7a7..ab1072d 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -5,6 +5,31 @@
 The third digit is only for regressions.
 
 
+17.2.0 (UNRELEASED)
+-------------------
+
+
+Backward-incompatible changes:
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+*none*
+
+
+Deprecations:
+^^^^^^^^^^^^^
+
+*none*
+
+
+Changes:
+^^^^^^^^
+
+*none*
+
+
+----
+
+
 17.1.0 (2017-06-30)
 -------------------
 
diff --git a/src/OpenSSL/version.py b/src/OpenSSL/version.py
index 634f85a..399c574 100644
--- a/src/OpenSSL/version.py
+++ b/src/OpenSSL/version.py
@@ -11,7 +11,7 @@
     "__title__", "__uri__", "__version__",
 ]
 
-__version__ = "17.1.0"
+__version__ = "17.2.0.dev0.0"
 
 __title__ = "pyOpenSSL"
 __uri__ = "https://pyopenssl.readthedocs.io/"