Fix z shift saving for piecewise mcorr (#314)

* Fix failure to compute correlation image for 3D data (pending caiman update)

* Fix by passing file as string and re-run without baseline if that fails

* Make local_correlations in cnmf compatible with 3D data

* Add z shifts for pw_rigid case

* Pin caiman version instead of catching error from old version

* Fix saving non-rigid z-shifts

mesmerize_core/algorithms/mcorr.py

@@ -112,7 +112,7 @@ def run_algo(batch_path, uuid, data_path: str = None):
             y_shifts = mc.y_shifts_els
             shifts = [x_shifts, y_shifts]
             if hasattr(mc, 'z_shifts_els'):
-                shifts += mc.z_shifts_els
+                shifts.append(mc.z_shifts_els)
             shift_path = output_dir.joinpath(f"{uuid}_shifts.npy")
             np.save(str(shift_path), shifts)
         else: