Update changes

CHANGES.rst

@@ -8,6 +8,7 @@ Here you can see the full list of changes between each SQLAlchemy-Utils release.
 ^^^^^^^^^^^^^^^^^^^
 
 - Added get_column_key
+- Added Timestamp model mixin
 
 
 0.26.4 (2014-06-25)

sqlalchemy_utils/models.py

@@ -10,9 +10,12 @@ class Timestamp(object):
     for all derived declarative models.
 
     ::
+
+
         import sqlalchemy as sa
         from sqlalchemy_utils import Timestamp
 
+
         class SomeModel(Base, Timestamp):
             __tablename__ = 'somemodel'
             id = sa.Column(sa.Integer, primary_key=True)