logilab-common #1716063 drop deprecated TestCase methods [validation pending]

we should have done this in 1.0...

prioritynormal
typeenhancement
done in1.1.0
load1.000
load left0.000
closed by#46afffcb247b [testlib] Remove deprecated assert methods
patch[testlib] Remove deprecated assert methods [applied][testlib] Remove old TestCase.assertRaises code [applied]