Bump SLF4J again to pick up bugfix
Bump SLF4J again to pick up bugfix

SLF4J 1.7.9 removes usage of @Nonnull,
which was causing problems for Scala programs.
gburton1/metrics,egymgmbh/metrics,chenxianghua2014/metrics,valery1707/dropwizard-metrics,mt0803/metrics,gburton1/metrics,wfxiang08/metrics,mspiegel/metrics,timezra/metrics,rexren/metrics,randomstatistic/metrics,tempredirect/metrics,signalfx/metrics,AltitudeDigital/metrics,kevintvh/metrics,cirrus-dev/metrics,ohr/metrics,jasw/metrics,mattnelson/metrics,jplock/metrics,bentatham/metrics,unitsofmeasurement/metrics,mtakaki/metrics,ind9/metrics,mnuessler/metrics,ChetnaChaudhari/metrics