updated maven plugin versions
updated maven plugin versions

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