Use assertAlmostEqual instead of failUnlessAlmostEqual in unit tests

The method failUnlessAlmostEqual has been deprecated since python 2.7.
http://docs.python.org/2/library/unittest.html#deprecated-aliases
Also in Python 3, a deprecated warning is raised when using
failUnlessAlmostEqual therefore we should use assertAlmostEqual instead.

Change-Id: Ic9947028afdb5b1ba8f19103018a6f1bc3fc551f
Closes-Bug: #1257068
Merge "Use assertAlmostEqual instead of failUnlessAlmostEqual in unit tests"