update test dependency

Author: hauner

openapi-processor-core/build.gradle

@@ -32,7 +32,7 @@ String getBuildSignKey(String property) {
 
 ext {
     processorApiVersion = '2021.1'
-    processorTestVersion = '2021.5-SNAPSHOT'
+    processorTestVersion = '2021.4'
     jacksonVersion = '2.12.3'
     groovyVersion = '3.0.8'