Add 2.5.2 in changelog

Author: Pierre-Sassoulas

ChangeLog

@@ -9,7 +9,7 @@ Release Date: TBA
 
 What's New in astroid 2.5.2?
 ============================
-Release Date: TBA
+Release Date: 2021-03-28
 
 * Detects `import numpy` as a valid `numpy` import.
 
@@ -19,7 +19,6 @@ Release Date: TBA
 
   Closes PyCQA/pylint#3202
 
-
 What's New in astroid 2.5.1?
 ============================
 Release Date: 2021-02-28

astroid/__pkginfo__.py

@@ -27,8 +27,8 @@
 """astroid packaging information"""
 
 # For an official release, use dev_version = None
-numversion = (2, 5, 1)
-dev_version = None
+numversion = (2, 5, 2)
+dev_version = 1
 
 version = ".".join(str(num) for num in numversion)
 if dev_version is not None: