Fix software SPI driver initializer to define MOSI, MISO, SS pins as optional.

Author: tdicola

Adafruit_GPIO/SPI.py

@@ -98,7 +98,7 @@ def transfer(self, data):
 class BitBang(object):
     """Software-based implementation of the SPI protocol over GPIO pins."""
 
-    def __init__(self, gpio, sclk, mosi, miso, ss):
+    def __init__(self, gpio, sclk, mosi=None, miso=None, ss=None):
         """Initialize bit bang (or software) based SPI.  Must provide a BaseGPIO
         class, the SPI clock, and optionally MOSI, MISO, and SS (slave select)
         pin numbers. If MOSI is set to None then writes will be disabled and fail

setup.py

@@ -11,7 +11,7 @@
     requires.append('spidev')
 
 setup(name              = 'Adafruit_GPIO',
-      version           = '0.8.1',
+      version           = '0.9.0',
       author            = 'Tony DiCola',
       author_email      = 'tdicola@adafruit.com',
       description       = 'Library to provide a cross-platform GPIO interface on the Raspberry Pi and Beaglebone Black using the RPi.GPIO and Adafruit_BBIO libraries.',