double timeout each try

@karnem this feature doubles the timeout each try while trying to send or retrieve a constant from database

cal_tools/cal_tools/tools.py

@@ -288,6 +288,7 @@ def get_from_db(device, constant, condition, empty_constant,
                 break
             except zmq.error.Again:
                 ntries -= 1
+                timeout *= 2
                 sleep(np.random.randint(30))
             except Exception as e:
                 if verbosity > 0:
@@ -354,6 +355,7 @@ def send_to_db(device, constant, condition, file_loc,
                 break
             except zmq.error.Again:
                 ntries -= 1
+                timeout *= 2
                 sleep(np.random.randint(30))
                 if ntries == 0 and doraise:
                     raise