fix: groovy dependency version (#3776)

core-groovy/src/main/groovy/com/baeldung/json/JsonParser.groovy

@@ -1,6 +1,5 @@
 package com.baeldung.json
 
-import groovy.json.JsonGenerator
 import groovy.json.JsonOutput
 import groovy.json.JsonParserType
 import groovy.json.JsonSlurper
@@ -21,14 +20,6 @@ class JsonParser {
         JsonOutput.toJson(account)
     }
 
-    String toJson(Account account, String dateFormat, String... fieldsToExclude) {
-        JsonGenerator generator = new JsonGenerator.Options()
-                .dateFormat(dateFormat)
-                .excludeFieldsByName(fieldsToExclude)
-                .build()
-        generator.toJson(account)
-    }
-
     String prettyfy(String json) {
         JsonOutput.prettyPrint(json)
     }

core-groovy/src/test/groovy/com/baeldung/json/JsonParserTest.groovy

@@ -52,20 +52,6 @@ class JsonParserTest extends Specification {
             json == '{"value":15.6,"createdAt":"2018-01-01T00:00:00+0000","id":"123"}'
     }
 
-    def 'Should parse to Json given an Account object, a date format and fields to exclude' () {
-        given:
-            Account account = new Account(
-                    id: '123',
-                    value: 15.6,
-                    createdAt: new SimpleDateFormat('MM/dd/yyyy').parse('01/01/2018')
-            )
-        when:
-            def json = jsonParser.toJson(account, 'MM/dd/yyyy', 'value')
-        then:
-            json
-            json == '{"createdAt":"01/01/2018","id":"123"}'
-    }
-
     def 'Should prettify given a json string' () {
         given:
             String json = '{"value":15.6,"createdAt":"01/01/2018","id":"123456"}'