adding ZmumuJets_Pt_20_300_GEN_13TeV_cfg.py to support 13 TeV relval set
Merge pull request #1675 from franzoni/add_ZmumuJets_Pt_20_300_GEN_13TeV_for_relval_CMSSW_7_0_X_2013-12-04-1400

adding ZmumuJets_Pt_20_300_GEN_13TeV_cfg.py to support 13 TeV relval set