Merge pull request #1530 from albayenes/connectivity-matrix-wrong-def…

…ault-parameter-in-doc-for-symmetric

Wrong default value for parameter 'symmetric' connectivity_matrix function

dipy/tracking/utils.py

@@ -134,7 +134,7 @@ def connectivity_matrix(streamlines, label_volume, voxel_size=None,
         This argument is deprecated.
     affine : array_like (4, 4)
         The mapping from voxel coordinates to streamline coordinates.
-    symmetric : bool, False by default
+    symmetric : bool, True by default
         Symmetric means we don't distinguish between start and end points. If
         symmetric is True, ``matrix[i, j] == matrix[j, i]``.
     return_mapping : bool, False by default