Update conf.py (#5518)

version bump to 2.5.0-beta2

Author: devyte

doc/conf.py

@@ -56,9 +56,9 @@
 # built documents.
 #
 # The short X.Y version.
-version = u'2.4.0'
+version = u'2.5.0-beta2'
 # The full version, including alpha/beta/rc tags.
-release = u'2.4.0'
+release = u'2.5.0-beta2'
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.