Fixed a release script and added a release date

CHANGES

@@ -3,7 +3,7 @@ Jinja2 Changelog
 
 Version 2.7
 -----------
-(codename to be selected, release date to be announced)
+(codename Translation, released on May 20th 2013)
 
 - Choice and prefix loaders now dispatch source and template lookup
   separately in order to work in combination with module loaders as

scripts/make-release.py

@@ -133,7 +133,7 @@ def main():
     if version in tags:
         fail('Version "%s" is already tagged', version)
     if release_date.date() != date.today():
-        fail('Release date is not today (%s != %s)')
+        fail('Release date is not today (%s != %s)', release_date.date(), date.today())
 
     if not git_is_clean():
         fail('You have uncommitted changes in git')