clean up unused Python imports (#454)

* Remove unused python imports

These changes have been auto-generated with:

	pip3 install isort autoflake
	isort -rc -sl .
	autoflake --remove-all-unused-imports -i -r .
	isort -rc -m 3 .

Signed-off-by: Radostin Stoyanov <rstoyanov@fedoraproject.org>

* python: remove redundant parenthesis

Signed-off-by: Radostin Stoyanov <rstoyanov@fedoraproject.org>

exercises/qos/receive.py

@@ -1,7 +1,8 @@
 #!/usr/bin/env python3
 
 import sys
-from scapy.all import sniff, get_if_list
+
+from scapy.all import sniff
 
 
 def handle_pkt(pkt):

exercises/qos/send.py

@@ -2,12 +2,10 @@
 
 import argparse
 import socket
-
-from scapy.all import sendp, send, hexdump, get_if_list, get_if_hwaddr
-from scapy.all import Ether, IP, UDP, TCP
-
 from time import sleep
 
+from scapy.all import IP, TCP, UDP, Ether, get_if_hwaddr, get_if_list, sendp
+
 
 def get_if():
     iface = None