Prepare 1.5.4 release

ChangeLog

@@ -2,7 +2,8 @@ ChangeLog for Pylint
 --------------------
---
+2016-01-15 -- 1.5.4
+
     * Merge StringMethodChecker with StringFormatChecker. This fixes a
       bug where disabling all the messages and enabling only a handful of
       messages from the StringFormatChecker would have resulted in no

pylint/__pkginfo__.py

@@ -23,7 +23,7 @@ from os.path import join
 modname = distname = 'pylint'
-numversion = (1, 5, 3)
+numversion = (1, 5, 4)
 version = '.'.join([str(num) for num in numversion])
 install_requires = [