Update dependency io.swagger:swagger-models to v1.6.6

Author: renovate-bot

build.gradle

@@ -38,7 +38,7 @@ dependencies {
     compile("io.springfox:springfox-swagger2:2.9.2")
     compile("io.springfox:springfox-swagger-ui:2.9.2")
     // https://github.com/swagger-api/swagger-core/issues/2783
-    compile("io.swagger:swagger-models:1.6.0")
+    compile("io.swagger:swagger-models:1.6.6")
     // end::swagger[]
     // tag::tests[]
     testCompile("org.springframework.boot:spring-boot-starter-test")