Add libpcap-dev to travis ci config
Add libpcap-dev to travis ci config

docsteer/sacnview,docsteer/sacnview,marcusbirkin/sacnview,marcusbirkin/sacnview,marcusbirkin/sacnview,docsteer/sacnview,docsteer/sacnview,marcusbirkin/sacnview,marcusbirkin/sacnview,marcusbirkin/sacnview,docsteer/sacnview,marcusbirkin/sacnview,docsteer/sacnview,docsteer/sacnview