update various maven plugin versions
update various maven plugin versions

DanySK/gson-extras,todoooo/gson,DanySK/gson-extras,testcenter/gson,todoooo/gson,testcenter/gson,mbrukman/gson,google/gson,mbrukman/gson,gv2011/jsoncore,mbrukman/gson,todoooo/gson,testcenter/gson,DanySK/gson-extras