Fixing python2.6 syntax errors

In python 2.6 the string .format(...) method cannot handle empty
brances within the string. i.e. 'instance name: {}'.format(name)
does not work.

The TestCase method assertIs does not exist in python 2.6.

Change-Id: I5628fba5f3319efe212ce6b92c5d04b5b4dacdf1