update plugins

Author: hauner

build.gradle

@@ -2,8 +2,8 @@ plugins {
     id 'java'
     id 'java-library'
     id 'maven-publish'
-    id 'com.jfrog.bintray' version '1.8.4'
-    id "com.github.ben-manes.versions" version "0.27.0"
+    id 'com.jfrog.bintray' version '1.8.5'
+    id "com.github.ben-manes.versions" version "0.28.0"
 }
 
 group 'com.github.hauner.openapi'