Remove message printed when library is loaded

Author: Techwolfy

adafruit_pcf8591/pcf8591.py

@@ -63,7 +63,6 @@ def __init__(self, i2c_bus, address=_PCF8591_DEFAULT_ADDR, reference_voltage=3.3
         else:
             raise ValueError("reference_voltage must be from 2.5 - 6.0")
         self._buffer = bytearray(2)
-        print("self.reference_voltage = ", self.reference_voltage)
         # possibly measure each channel here to prep readings for
         # user calls to `read`