Updated calculator.py to return error json messages instead of stack traces...
requested to merge 9-ensure-that-the-calculator-service-still-functions-and-returns-a-json-result-if-the-random-number-service-is-down into Development
Updated calculator.py to return error json messages instead of stack traces when other services are down.
Will be revisited when healthcheck issue is started so that services are aware of other services status.
Closes #9 (closed) Closes #10 (closed)