append notification_email to travis configuration for coverity plugins
append notification_email to travis configuration for coverity plugins

ferstar/h264_v4l2_rtspserver,Shahrozetariq/Smartta-Home,mpromonet/v4l2rtspserver,mpromonet/v4l2rtspserver,longcongduoi/h264_v4l2_rtspserver,mpromonet/h264_v4l2_rtspserver,mpromonet/v4l2rtspserver