Fix missing plugin and deprecation (#454)

* fix missing plugin

* update unittest

Author: fredroy

bindings/Sofa/tests/Core/Mass.py

@@ -15,6 +15,7 @@ def simulate_beam(linear_solver_template):
 
         root.addObject('DefaultAnimationLoop')
 
+        root.addObject('RequiredPlugin', name='Sofa.Component.StateContainer')
         root.addObject('RequiredPlugin', name='Sofa.Component.ODESolver.Backward')
         root.addObject('RequiredPlugin', name='Sofa.Component.LinearSolver.Direct')
         root.addObject('RequiredPlugin', name='Sofa.Component.Engine.Select')

bindings/SofaRuntime/tests/SofaRuntime/Base.py

@@ -12,5 +12,5 @@ def test_getCategoriesmethod(self):
         import SofaRuntime
         SofaRuntime.importPlugin("Sofa.Component")
         t = SofaRuntime.getCategories("MeshOBJLoader")
-        self.assertEquals(len(t),1)
+        self.assertEqual(len(t),1)
         self.assertIsInstance(t, list)