GH AllenInstitute#533 - Changed order of autobias_v in Sweep()

autobias_v was out of order and disrupting the other positional arguments.
It has been moved and set to None as default.

Author: ru57y34nn

ipfx/sweep.py

@@ -2,7 +2,7 @@
 
 
 class Sweep(object):
-    def __init__(self, t, v, i, clamp_mode, autobias_v, sampling_rate, sweep_number=None, epochs=None):
+    def __init__(self, t, v, i, clamp_mode, sampling_rate, sweep_number=None, epochs=None, autobias_v=None):
         self._t = t
         self._v = v
         self._i = i