Merge pull request #3 from Lucretiel/master

Specify seven data bits in the serial interface.

pyserial defaults to 8, but the Alpha protocol calls for 7.

alphasign/interfaces/local.py

@@ -28,6 +28,7 @@ class Serial(base.BaseInterface):
                                baudrate=4800,
                                parity=serial.PARITY_EVEN,
                                stopbits=serial.STOPBITS_TWO,
+                               bytesize=serial.SEVENBITS,
                                timeout=1,
                                xonxoff=0,
                                rtscts=0)