Upgrade to Spring Cloud Finchley #72 (#80)

* #72 Upgrade to Spring Cloud Finchley M9

* #72 Upgrade to Spring Boot 2.0.1

* #72 Remove @Deprecated API usage

* #72 Upgrade to Spring Cloud Finchley RC2, Spring Boot 2.0.2, Sleuth 2.0.0.RC2, Zipkin Server 2.8.4

* #72 Registering the index ViewController is no more required

* For logging, implement the toString() method of the Pet entity

* #72 Upgrade to Spring Boot Admin 2.0.0

* #72 Add @NoArgsConstructor required for Jackson deserialization

* #72 Upgrade to Spring Boot 2.0.3

* #72 Upgrade to Spring Cloud Finchley RELEASE

* Change Zipkin local host URL

* #72 changes requested by the @mszarlinski code review