Add Web service to retrieve cities inside a given perimeter

src/main/java/fr/ippon/geohipster/domain/Geocity.java

...ava/fr/ippon/geohipster/repository/GeocityRepository.java

...main/java/fr/ippon/geohipster/service/GeocityService.java

.../fr/ippon/geohipster/service/impl/GeocityServiceImpl.java

...in/java/fr/ippon/geohipster/web/rest/GeocityResource.java

...quibase/changelog/20170914101249_added_entity_Geocity.xml