Clean up imports

Author: CalemRoelofsSB

modules/swagger-parser-v3/src/main/java/io/swagger/v3/parser/util/DeserializationUtils.java

@@ -4,7 +4,6 @@
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.SerializationFeature;
-import com.fasterxml.jackson.dataformat.yaml.YAMLMapper;
 import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
 import io.swagger.v3.core.util.Yaml;
 import io.swagger.v3.core.util.Json;