Model classes and various method parameters declared final.

As the model classes are not designed for inheritance, they are now explicitly declared final.
Same for various input parameters, as thes should be immutable in most methods.

src/main/java/de/stklcode/jvault/connector/model/response/AuthMethodsResponse.java

@@ -32,7 +32,7 @@ import java.util.Map;
  * @since   0.1
  */
 @JsonIgnoreProperties(ignoreUnknown = true)
-public class AuthMethodsResponse extends VaultDataResponse {
+public final class AuthMethodsResponse extends VaultDataResponse {
     private Map<String, AuthMethod> supportedMethods;
 
     public AuthMethodsResponse() {
@@ -40,7 +40,7 @@ public class AuthMethodsResponse extends VaultDataResponse {
     }
 
     @Override
-    public void setData(Map<String, Object> data) throws InvalidResponseException {
+    public void setData(final Map<String, Object> data) throws InvalidResponseException {
         ObjectMapper mapper = new ObjectMapper();
         for (String path : data.keySet()) {
             try {