EDSC-245: Allow echo endpoint to be configured
EDSC-245: Allow echo endpoint to be configured

bilts/earthdata-search,mightynimble/earthdata-search,mightynimble/earthdata-search,bilts/earthdata-search,mightynimble/earthdata-search,bilts/earthdata-search,bilts/earthdata-search,mightynimble/earthdata-search