Update changelog for Chico Beta1 release

Author: renanrodrigo

CHANGELOG.rst

@@ -1,7 +1,7 @@
 ##########
 Change log
 ##########
-All notable changes to the python-openflow project is documented in this file.
+All notable changes to the python-openflow project are documented in this file.
 
 UNRELEASED - Under development
 ******************************
@@ -24,27 +24,40 @@ Security
 ========
 
 
-[2017.1] - "bethania" - 2017-07-06
-**********************************
+[2017.2b1] - "chico" beta1 - 2017-09-18
+***************************************
 Added
 =====
+- OpenFlow Extensible Match structures.
+- ARP packet pack/unpack support.
+- 802.1q VLAN packet pack/unpack support.
 
 Changed
 =======
-- Documentation updated and improved.
-
-Deprecated
-==========
+- Improved packet validation and unpacking.
+- Yala substitutes Pylama as the main linter checker.
+- Requirements files updated and restructured.
 
 Removed
 =======
+- Unused and duplicated files.
 
 Fixed
 =====
-- Some bug fixes
+- Some missing classes and elements were included.
+- Some test fixes.
+- Several bug fixes.
 
-Security
-========
+
+[2017.1] - "bethania" - 2017-07-06
+**********************************
+Changed
+=======
+- Documentation updated and improved.
+
+Fixed
+=====
+- Some bug fixes.
 
 
 [2017.1b3] - "bethania" beta3 - 2017-06-16