Fix syntax error

Author: canyon289

pymc/tests/test_distributions.py

@@ -2623,7 +2623,7 @@ def test_interpolated_transform(self, transform):
     def test_grw(self):
         self.check_logp(
             pm.GaussianRandomWalk,
-            Vector(R, 10)
+            Vector(R, 10),
             {"mu": R, "sigma": Rplus, "steps": Nat},
             lambda value, mu, sigma: sp.norm.logpdf(value, mu, sigma).cumsum().sum(),
             decimal=select_by_precision(float64=6, float32=1),