readd mu 2-dim test cases

Author: yadav-sachin

pymc/tests/test_distributions_moments.py

@@ -759,6 +759,9 @@ def test_categorical_moment(p, size, expected):
         (np.ones(10), np.identity(10), None, np.ones(10)),
         (np.ones(2), np.identity(2), 4, np.ones((4, 2))),
         (np.ones(2), np.identity(2), (4, 3), np.ones((4, 3, 2))),
+        (np.ones((2, 2)), np.identity(2), None, np.ones((2, 2))),
+        (np.ones((2, 2)), np.identity(2), 4, np.ones((4, 2, 2))),
+        (np.ones((2, 2)), np.identity(2), (4, 2), np.ones((4, 2, 2, 2))),
         (np.array([1, 0, 3.0]), np.identity(3), None, np.array([1, 0, 3.0])),
         (np.array([1, 0, 3.0]), np.identity(3), 4, np.full((4, 3), [1, 0, 3.0])),
         (np.array([1, 0, 3.0]), np.identity(3), (4, 2), np.full((4, 2, 3), [1, 0, 3.0])),
@@ -780,6 +783,12 @@ def test_categorical_moment(p, size, expected):
             (4, 5),
             np.full((4, 5, 3), [1, 3, 0.0]),
         ),
+        (
+            np.array([[3., 5], [1, 4]]),
+            np.identity(2),
+            (4, 5),
+            np.full((4, 5, 2, 2), [[3., 5], [1, 4]])
+        ),
     ],
 )
 def test_mv_normal_moment(mu, cov, size, expected):