set version of assertj back to 1.6.1 due to incompatibility with jdk6
set version of assertj back to 1.6.1 due to incompatibility with jdk6

artspb/pitest,mzw/pitest,artspb/pitest,mzw/pitest,velo/pitest,august782/pitest,artspb/pitest,velo/pitest,hcoles/pitest,august782/pitest,lkwg82/pitest,jacksonpradolima/pitest,velo/pitest,jasonmfehr/pitest,jasonmfehr/pitest,hcoles/pitest,jacksonpradolima/pitest,lkwg82/pitest,jacksonpradolima/pitest,lkwg82/pitest,jasonmfehr/pitest,august782/pitest,mzw/pitest