attenuation-control: Add scripts to control the attenuation

Xmlrpc client/server application to control the digital attenuators
installed in the lava testbed.

Implements AR_VUL-64.

Signed-off-by: Thomas Klaehn <thomas.klaehn@u-blox.com>

mock/IOPi/__init__.py

@@ -0,0 +1,22 @@
+class IOPi(object):
+    address = None
+    used_pins = [0 for i in range(17)]
+    pin_directions = [0 for i in range(17)]
+    pin_values = [0 for i in range(17)]
+
+    def __init__(self, address):
+        self.address = address
+
+    def set_pin_direction(self, pin, direction):
+        self.used_pins[pin] = 1
+        self.pin_directions[pin] = direction
+
+    def write_pin(self, pin, value):
+        self.used_pins[pin] = 1
+        self.pin_values[pin] = value
+
+    def read_pin(self, pin):
+        if self.used_pins[pin] == 1:
+            return self.pin_values[pin]
+        else:
+            return None