Travis reported another false negative, if paramiko was present but version too low for marvin, nosetests wouldn't run and result would be success

Signed-off-by: Daan Hoogland <daan@onecht.net>

tools/travis/before_install.sh

@@ -83,6 +83,7 @@ echo -e "\nInstalling some python packages: "
 for ((i=0;i<$RETRY_COUNT;i++))
 do
   sudo pip install lxml texttable > /tmp/piplog
+  sudo pip install --upgrade paramiko >> /tmp/piplog
   if [[ $? -eq 0 ]]; then
     echo -e "\npython packages installed successfully"
     break;