fix: add install of stix2 packages to support STIX 2.0 export
fix: add install of stix2 packages to support STIX 2.0 export

SteveClement/MISP,devnull-/MISP,devnull-/MISP,MISP/MISP,devnull-/MISP,Rafiot/MISP,MISP/MISP,SteveClement/MISP,TheDr1ver/MISP,MISP/MISP,FIRSTdotorg/MISP,devnull-/MISP,FloatingGhost/MISP,SteveClement/MISP,TheDr1ver/MISP,TheDr1ver/MISP,FIRSTdotorg/MISP,MISP/MISP,TheDr1ver/MISP,Rafiot/MISP,FloatingGhost/MISP,MISP/MISP,FIRSTdotorg/MISP,FIRSTdotorg/MISP,Rafiot/MISP,Rafiot/MISP,SteveClement/MISP,SteveClement/MISP,FloatingGhost/MISP,FloatingGhost/MISP