[WIP] api-client: add circuit breaker with resillience4j

[adhikasp]

This add circuit breaking mechanism using spring-cloud-circuitbreaker and resillience4j implementation.

TODO

• [x] Draft POC of working ApiClient with circuit breaker - DONE, see sample log on helloApiClient is OPEN thus prevent HTTP API call to happen.
• [ ] Expose circuit breaker configuration to ApiClientProperties
• [ ] Proper test
• [ ] Update readme

2020-06-11 03:10:30.644 ERROR [,,,] 477254 --- [           main] c.b.o.b.a.error.DefaultApiErrorResolver  : CircuitBreaker 'helloApiClient' is OPEN and does not permit further calls

io.github.resilience4j.circuitbreaker.CallNotPermittedException: CircuitBreaker 'helloApiClient' is OPEN and does not permit further calls