Update checkstyle 7.6.1 -> 8.0
Update checkstyle 7.6.1 -> 8.0

JabRef/jabref,JabRef/jabref,sauliusg/jabref,zellerdev/jabref,tobiasdiez/jabref,oscargus/jabref,shitikanth/jabref,shitikanth/jabref,tobiasdiez/jabref,zellerdev/jabref,tobiasdiez/jabref,Siedlerchr/jabref,sauliusg/jabref,shitikanth/jabref,zellerdev/jabref,shitikanth/jabref,Siedlerchr/jabref,oscargus/jabref,JabRef/jabref,Siedlerchr/jabref,sauliusg/jabref,oscargus/jabref,zellerdev/jabref,Siedlerchr/jabref,oscargus/jabref,zellerdev/jabref,sauliusg/jabref,JabRef/jabref,oscargus/jabref,shitikanth/jabref,tobiasdiez/jabref