Python 3: Remove long value check

In python 3 the two types int and long have been unified into one. This
patch fixes a syntax error that would occur in python3 and ensures that
we test it when using python 2.

closes-bug: 1403226
Partially implements blueprint: support-python3

Change-Id: Idd05bba57cdf3b384ed2e11817e97d21518ec980
Merge "Python 3: Remove long value check"