Add doxygen regression test to travis
Add doxygen regression test to travis

arurke/contiki,MohamedSeliem/contiki,bluerover/6lbr,arurke/contiki,MohamedSeliem/contiki,arurke/contiki,MohamedSeliem/contiki,MohamedSeliem/contiki,bluerover/6lbr,bluerover/6lbr,bluerover/6lbr,arurke/contiki,MohamedSeliem/contiki,MohamedSeliem/contiki,arurke/contiki,arurke/contiki,MohamedSeliem/contiki,arurke/contiki,bluerover/6lbr,bluerover/6lbr,bluerover/6lbr