Update before_install.sh

Author: DaanHoogland

tools/travis/before_install.sh

@@ -114,7 +114,6 @@ echo -e "\nInstalling some python packages: "
 for ((i=0;i<$RETRY_COUNT;i++))
 do
   python3 -m pip install --user --upgrade urllib3 lxml paramiko nose texttable ipmisim pyopenssl pycrypto mock flask netaddr pylint pycodestyle six astroid > /tmp/piplog
-  python2 -m pip install --user --upgrade pylint pycodestyle >> /tmp/piplog
   if [[ $? -eq 0 ]]; then
     echo -e "\npython packages installed successfully"
     break;
@@ -124,4 +123,4 @@ do
 done
 
 echo -e "\nVersion of pip packages:\n"
-echo $(pip freeze)
+echo $(pip freeze)