Change sleep timer to be longer for test_rpc_calculator

Hopefully this fixes timing issues with the test on travisci

test/test_rpc_calculator.py

@@ -21,7 +21,7 @@ def test_calculator():
 
 def run_subprocesses(address):
     server = subprocess.Popen([examples_dir + '/calculator_server.py', address])
-    time.sleep(.1)  # Give the server some small amount of time to start listening
+    time.sleep(2)  # Give the server some small amount of time to start listening
     client = subprocess.Popen([examples_dir + '/calculator_client.py', address])
 
     ret = client.wait()