Fix typos and date formats in changelog

Author: renanrodrigo

CHANGELOG.rst

@@ -21,8 +21,8 @@ Changed
 =======
 - Enums of the OpenFlow structures changed to IntEnums, to make easier
   comparisons with integer values.
-- updated requirements.txt
-- 'data' fields included for symmetric messages as echo requests/replies.
+- Updated requirements.txt
+- 'data' fields included for symmetric messages, like echo requests/replies.
 - Documentation updated.
 
 Removed
@@ -35,7 +35,7 @@ Fixed
 - Several bug fixes.
 
 
-[2017.1b1] - "bethania" beta1 - 2017-24-03
+[2017.1b1] - "bethania" beta1 - 2017-03-24
 ******************************************
 Added
 =====
@@ -67,7 +67,7 @@ Changed
 - Adding constant files to manage constants in NApps
 - Moving foundation module to pyof root folder (same with tests)
 
-[2016.2a1] - alpha1 - 2016-11-09
+[2016.2a1] - alpha1 - 2016-09-11
 ********************************
 Changed
 =======
@@ -77,7 +77,7 @@ Changed
 - lint fixes and docs generation
 - Pip support
 
-[2016.1a1] - alpha1 - 2016-06-08
+[2016.1a1] - alpha1 - 2016-08-06
 ********************************
 Changed
 =======
@@ -141,7 +141,7 @@ Changed
 - better organization on problem description
 - added messages, todo and instructions
 
-[2013.1a1] - Initial - 2013-06-08
+[2013.1a1] - Initial - 2013-08-06
 *********************************
 Added
 =====