Remove Constant step method test

Author: fonnesbeck

pymc3/tests/test_step.py

@@ -5,7 +5,7 @@
 from pymc3.sampling import assign_step_methods, sample
 from pymc3.model import Model
 from pymc3.step_methods import (NUTS, BinaryGibbsMetropolis, CategoricalGibbsMetropolis,
-                                Metropolis, Constant, Slice, CompoundStep,
+                                Metropolis, Slice, CompoundStep,
                                 MultivariateNormalProposal, HamiltonianMC)
 from pymc3.distributions import Binomial, Normal, Bernoulli, Categorical
 from numpy.testing import assert_almost_equal
@@ -68,14 +68,6 @@ def test_step_categorical(self):
             self.check_stat(check, trace)
 
 
-    def test_constant_step(self):
-        with Model():
-            x = Normal('x', 0, 1)
-            start = {'x': -1}
-            tr = sample(10, step=Constant([x]), start=start)
-        assert_almost_equal(tr['x'], start['x'], decimal=10)
-
-
 class TestCompoundStep(unittest.TestCase):
     samplers = (Metropolis, Slice, HamiltonianMC, NUTS)