[NIFI-3507]-Update NiFi-assembly Java Requirement to 1.8
[NIFI-3507]-Update NiFi-assembly Java Requirement to 1.8

This closes #1531.

Signed-off-by: Aldrin Piri <8746015474cd01110181ed51735247560fd08de4@apache.org>

ShellyLC/nifi,Xsixteen/nifi,ijokarumawak/nifi,tijoparacka/nifi,joetrite/nifi,speddy93/nifi,josephxsxn/nifi,ShellyLC/nifi,zhengsg/nifi,bbende/nifi,PuspenduBanerjee/nifi,alopresto/nifi,trixpan/nifi,ijokarumawak/nifi,mcgilman/nifi,mattyb149/nifi,peter-gergely-horvath/nifi,speddy93/nifi,pvillard31/nifi,mans2singh/nifi,bbende/nifi,michalklempa/nifi,dlukyanov/nifi,PuspenduBanerjee/nifi,ShellyLC/nifi,trixpan/nifi,jskora/nifi,mcgilman/nifi,thesolson/nifi,alopresto/nifi,jskora/nifi,jtstorck/nifi,Wesley-Lawrence/nifi,joewitt/incubator-nifi,aperepel/nifi,qfdk/nifi,apsaltis/nifi,peter-gergely-horvath/nifi,MikeThomsen/nifi,peter-gergely-horvath/nifi,jfrazee/nifi,bbende/nifi,WilliamNouet/nifi,joetrite/nifi,pvillard31/nifi,Xsixteen/nifi,apsaltis/nifi,zhengsg/nifi,tequalsme/nifi,WilliamNouet/ApacheNiFi,MikeThomsen/nifi,jfrazee/nifi,joetrite/nifi,alopresto/nifi,mans2singh/nifi,alopresto/nifi,aperepel/nifi,aperepel/nifi,WilliamNouet/nifi,patricker/nifi,WilliamNouet/ApacheNiFi,aperepel/nifi,patricker/nifi,jtstorck/nifi,Xsixteen/nifi,dlukyanov/nifi,qfdk/nifi,Wesley-Lawrence/nifi,jjmeyer0/nifi,PuspenduBanerjee/nifi,thesolson/nifi,jfrazee/nifi,m-hogue/nifi,tijoparacka/nifi,Wesley-Lawrence/nifi,speddy93/nifi,qfdk/nifi,PuspenduBanerjee/nifi,mans2singh/nifi,mcgilman/nifi,michalklempa/nifi,m-hogue/nifi,dlukyanov/nifi,MikeThomsen/nifi,m-hogue/nifi,WilliamNouet/ApacheNiFi,pvillard31/nifi,MikeThomsen/nifi,jtstorck/nifi,YolandaMDavis/nifi,peter-gergely-horvath/nifi,patricker/nifi,mattyb149/nifi,josephxsxn/nifi,alopresto/nifi,patricker/nifi,YolandaMDavis/nifi,trixpan/nifi,qfdk/nifi,josephxsxn/nifi,jjmeyer0/nifi,mattyb149/nifi,aperepel/nifi,apsaltis/nifi,tequalsme/nifi,dlukyanov/nifi,josephxsxn/nifi,zhengsg/nifi,MikeThomsen/nifi,joewitt/incubator-nifi,jskora/nifi,ijokarumawak/nifi,mattyb149/nifi,InspurUSA/nifi,josephxsxn/nifi,YolandaMDavis/nifi,WilliamNouet/nifi,mattyb149/nifi,aperepel/nifi,michalklempa/nifi,WilliamNouet/nifi,mcgilman/nifi,thesolson/nifi,thesolson/nifi,patricker/nifi,apsaltis/nifi,bbende/nifi,tijoparacka/nifi,ijokarumawak/nifi,alopresto/nifi,tijoparacka/nifi,tijoparacka/nifi,joewitt/incubator-nifi,mattyb149/nifi,pvillard31/nifi,ShellyLC/nifi,WilliamNouet/ApacheNiFi,peter-gergely-horvath/nifi,InspurUSA/nifi,mcgilman/nifi,jskora/nifi,jjmeyer0/nifi,speddy93/nifi,josephxsxn/nifi,ijokarumawak/nifi,trixpan/nifi,jfrazee/nifi,thesolson/nifi,tequalsme/nifi,trixpan/nifi,MikeThomsen/nifi,apsaltis/nifi,jfrazee/nifi,YolandaMDavis/nifi,michalklempa/nifi,InspurUSA/nifi,apsaltis/nifi,jfrazee/nifi,mans2singh/nifi,WilliamNouet/ApacheNiFi,tijoparacka/nifi,mcgilman/nifi,m-hogue/nifi,MikeThomsen/nifi,jtstorck/nifi,dlukyanov/nifi,peter-gergely-horvath/nifi,m-hogue/nifi,speddy93/nifi,m-hogue/nifi,mattyb149/nifi,Wesley-Lawrence/nifi,zhengsg/nifi,InspurUSA/nifi,InspurUSA/nifi,jfrazee/nifi,michalklempa/nifi,jjmeyer0/nifi,YolandaMDavis/nifi,joewitt/incubator-nifi,ShellyLC/nifi,dlukyanov/nifi,pvillard31/nifi,bbende/nifi,michalklempa/nifi,Xsixteen/nifi,YolandaMDavis/nifi,jjmeyer0/nifi,zhengsg/nifi,Wesley-Lawrence/nifi,joewitt/incubator-nifi,bbende/nifi,mcgilman/nifi,m-hogue/nifi,WilliamNouet/nifi,PuspenduBanerjee/nifi,patricker/nifi,trixpan/nifi,joetrite/nifi,zhengsg/nifi,speddy93/nifi,mans2singh/nifi,pvillard31/nifi,patricker/nifi,WilliamNouet/nifi,PuspenduBanerjee/nifi,pvillard31/nifi,tequalsme/nifi,mans2singh/nifi,tequalsme/nifi,pvillard31/nifi,joetrite/nifi,qfdk/nifi,InspurUSA/nifi,joewitt/incubator-nifi,WilliamNouet/ApacheNiFi,jtstorck/nifi,qfdk/nifi,Xsixteen/nifi,joetrite/nifi,Xsixteen/nifi,jjmeyer0/nifi,Wesley-Lawrence/nifi,YolandaMDavis/nifi,tequalsme/nifi,jtstorck/nifi,jtstorck/nifi,ijokarumawak/nifi,jskora/nifi,ShellyLC/nifi,jskora/nifi,thesolson/nifi,alopresto/nifi,jfrazee/nifi