travis: added "make docs"
travis: added "make docs"

sradanov/flyingpigeon,KatiRG/flyingpigeon,KatiRG/flyingpigeon,KatiRG/flyingpigeon,KatiRG/flyingpigeon,sradanov/flyingpigeon,sradanov/flyingpigeon,bird-house/flyingpigeon,KatiRG/flyingpigeon,sradanov/flyingpigeon,sradanov/flyingpigeon