EventEmitter warning / memory leak

[aneilbaboo]

Getting a memory leak when running tests. It looks like it is due to the Winston logger:
(node --trace-warnings allows us to see the stack):

$ yarn test:trace
Loading test-offline.env environment
Serverless: Generating offline settings
 PASS  src/services/report/resolvers.test.ts
 PASS  src/services/report/services/smart-report/personalizer.test.ts
 PASS  src/services/system/service.test.ts
 PASS  src/services/variant-call/models.test.ts
 PASS  src/services/report/models.test.ts
 PASS  src/services/graphql/handler.test.ts
 PASS  src/services/report/schema.test.ts
 PASS  src/services/auth/auth0.test.ts
 PASS  src/services/models.test.ts
 PASS  src/services/report/services/smart-report/data-types/variant-call/function.test.ts
 PASS  src/services/system/models/variant-requirement.test.ts
 PASS  src/services/variant-call/service.test.ts
(node:60023) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 unpipe listeners added. Use emitter.setMaxListeners() to increase limit
    at _addListener (events.js:280:19)
    at Console.addListener (events.js:297:10)
    at DerivedLogger.Object.<anonymous>.Readable.pipe (/Users/aneil/code/precisely/web/app-backend/node_modules/readable-stream/lib/_stream_readable.js:564:8)
    at DerivedLogger.add (/Users/aneil/code/precisely/web/app-backend/node_modules/winston/lib/winston/logger.js:279:10)
    at transports.forEach.transport (/Users/aneil/code/precisely/web/app-backend/node_modules/winston/lib/winston/logger.js:79:44)
    at Array.forEach (<anonymous>)
    at DerivedLogger.configure (/Users/aneil/code/precisely/web/app-backend/node_modules/winston/lib/winston/logger.js:79:18)
    at new Logger (/Users/aneil/code/precisely/web/app-backend/node_modules/winston/lib/winston/logger.js:35:10)
    at new DerivedLogger (/Users/aneil/code/precisely/web/app-backend/node_modules/winston/lib/winston/create-logger.js:28:5)
    at Object.<anonymous>.module.exports [as createLogger] (/Users/aneil/code/precisely/web/app-backend/node_modules/winston/lib/winston/create-logger.js:81:3)
(node:60023) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 error listeners added. Use emitter.setMaxListeners() to increase limit
    at _addListener (events.js:280:19)
    at Console.prependListener (events.js:304:14)
    at prependListener (/Users/aneil/code/precisely/web/app-backend/node_modules/readable-stream/lib/_stream_readable.js:92:69)
    at DerivedLogger.Object.<anonymous>.Readable.pipe (/Users/aneil/code/precisely/web/app-backend/node_modules/readable-stream/lib/_stream_readable.js:644:3)
    at DerivedLogger.add (/Users/aneil/code/precisely/web/app-backend/node_modules/winston/lib/winston/logger.js:279:10)
    at transports.forEach.transport (/Users/aneil/code/precisely/web/app-backend/node_modules/winston/lib/winston/logger.js:79:44)
    at Array.forEach (<anonymous>)
    at DerivedLogger.configure (/Users/aneil/code/precisely/web/app-backend/node_modules/winston/lib/winston/logger.js:79:18)
    at new Logger (/Users/aneil/code/precisely/web/app-backend/node_modules/winston/lib/winston/logger.js:35:10)
    at new DerivedLogger (/Users/aneil/code/precisely/web/app-backend/node_modules/winston/lib/winston/create-logger.js:28:5)
(node:60023) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 drain listeners added. Use emitter.setMaxListeners() to increase limit
    at _addListener (events.js:280:19)
    at Console.addListener (events.js:297:10)
    at DerivedLogger.Object.<anonymous>.Readable.pipe (/Users/aneil/code/precisely/web/app-backend/node_modules/readable-stream/lib/_stream_readable.js:585:8)
    at DerivedLogger.add (/Users/aneil/code/precisely/web/app-backend/node_modules/winston/lib/winston/logger.js:279:10)
    at transports.forEach.transport (/Users/aneil/code/precisely/web/app-backend/node_modules/winston/lib/winston/logger.js:79:44)
    at Array.forEach (<anonymous>)
    at DerivedLogger.configure (/Users/aneil/code/precisely/web/app-backend/node_modules/winston/lib/winston/logger.js:79:18)
    at new Logger (/Users/aneil/code/precisely/web/app-backend/node_modules/winston/lib/winston/logger.js:35:10)
    at new DerivedLogger (/Users/aneil/code/precisely/web/app-backend/node_modules/winston/lib/winston/create-logger.js:28:5)
    at Object.<anonymous>.module.exports [as createLogger] (/Users/aneil/code/precisely/web/app-backend/node_modules/winston/lib/winston/create-logger.js:81:3)
(node:60023) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 close listeners added. Use emitter.setMaxListeners() to increase limit
    at _addListener (events.js:280:19)
    at Console.addListener (events.js:297:10)
    at Console.once (events.js:341:8)
    at DerivedLogger.Object.<anonymous>.Readable.pipe (/Users/aneil/code/precisely/web/app-backend/node_modules/readable-stream/lib/_stream_readable.js:651:8)
    at DerivedLogger.add (/Users/aneil/code/precisely/web/app-backend/node_modules/winston/lib/winston/logger.js:279:10)
    at transports.forEach.transport (/Users/aneil/code/precisely/web/app-backend/node_modules/winston/lib/winston/logger.js:79:44)
    at Array.forEach (<anonymous>)
    at DerivedLogger.configure (/Users/aneil/code/precisely/web/app-backend/node_modules/winston/lib/winston/logger.js:79:18)
    at new Logger (/Users/aneil/code/precisely/web/app-backend/node_modules/winston/lib/winston/logger.js:35:10)
    at new DerivedLogger (/Users/aneil/code/precisely/web/app-backend/node_modules/winston/lib/winston/create-logger.js:28:5)
(node:60023) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 finish listeners added. Use emitter.setMaxListeners() to increase limit
    at _addListener (events.js:280:19)
    at Console.addListener (events.js:297:10)
    at Console.once (events.js:341:8)
    at DerivedLogger.Object.<anonymous>.Readable.pipe (/Users/aneil/code/precisely/web/app-backend/node_modules/readable-stream/lib/_stream_readable.js:657:8)
    at DerivedLogger.add (/Users/aneil/code/precisely/web/app-backend/node_modules/winston/lib/winston/logger.js:279:10)
    at transports.forEach.transport (/Users/aneil/code/precisely/web/app-backend/node_modules/winston/lib/winston/logger.js:79:44)
    at Array.forEach (<anonymous>)
    at DerivedLogger.configure (/Users/aneil/code/precisely/web/app-backend/node_modules/winston/lib/winston/logger.js:79:18)
    at new Logger (/Users/aneil/code/precisely/web/app-backend/node_modules/winston/lib/winston/logger.js:35:10)
    at new DerivedLogger (/Users/aneil/code/precisely/web/app-backend/node_modules/winston/lib/winston/create-logger.js:28:5)

See: winstonjs/winston#1334