Update ConfiguringTestTarget.md
Update ConfiguringTestTarget.md

1) Update gbcmdert_target.conf sample to include current file variables
2) Simplify SSL Certificate Retrieval and Installation command line contents to clarify gbcmdcert_target variable names and static GBA AWS SSL Certificate file names, and static CA Certificate and Stunnel directories.
MartyBurns/OpenESPI-GreenButtonCMDTest,RonPasquarelli/OpenESPI-GreenButtonCMDTest,energyos/OpenESPI-GreenButtonCMDTest,dfcoffin/OpenESPI-GreenButtonCMDTest,RonPasquarelli/OpenESPI-GreenButtonCMDTest,MartyBurns/OpenESPI-GreenButtonCMDTest,energyos/OpenESPI-GreenButtonCMDTest,dfcoffin/OpenESPI-GreenButtonCMDTest