Add IS_UNIT_TEST_ENV which is required by conditional opensearch document setup

[weilu]

Also minor fix for README instruction json file path

[delcroip]

@weilu is the variable name important ? (in // I added IS_TESTING with the same definition)

[weilu]

@weilu is the variable name important ? (in // I added IS_TESTING with the same definition)

@delcroip Where did you add IS_TESTING?

[weilu]

@delcroip the var name is important because it's already used by existing modules, for example: https://github.com/openimis/openimis-be-individual_py/blob/develop/individual/documents.py#L4