fixes #43 update TokenHelper to OauthHelper

Author: stevehu

authorize/src/test/java/com/networknt/oauth/authorize/handler/Oauth2AuthorizeGetHandlerTest.java

@@ -15,7 +15,7 @@
 
 import java.net.ConnectException;
 
-import static com.networknt.client.oauth.TokenHelper.encodeCredentials;
+import static com.networknt.client.oauth.OauthHelper.encodeCredentials;
 
 
 /**

code/src/test/java/com/networknt/oauth/code/handler/Oauth2CodeGetHandlerTest.java

@@ -15,7 +15,7 @@
 
 import java.net.ConnectException;
 
-import static com.networknt.client.oauth.TokenHelper.encodeCredentials;
+import static com.networknt.client.oauth.OauthHelper.encodeCredentials;
 
 
 /**

code/src/test/java/com/networknt/oauth/code/handler/Oauth2CodePostHandlerTest.java

@@ -1,30 +1,22 @@
 package com.networknt.oauth.code.handler;
 
-import com.networknt.client.Client;
-import com.networknt.exception.ApiException;
-import com.networknt.exception.ClientException;
 import org.apache.commons.io.IOUtils;
 import org.apache.http.NameValuePair;
 import org.apache.http.client.entity.UrlEncodedFormEntity;
 import org.apache.http.client.methods.CloseableHttpResponse;
-import org.apache.http.client.methods.HttpGet;
 import org.apache.http.client.methods.HttpPost;
-import org.apache.http.entity.StringEntity;
 import org.apache.http.impl.client.CloseableHttpClient;
 import org.apache.http.impl.client.HttpClients;
 import org.apache.http.message.BasicNameValuePair;
-import org.junit.Assert;
 import org.junit.ClassRule;
 import org.junit.Test;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.net.ConnectException;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
-import static com.networknt.client.oauth.TokenHelper.encodeCredentials;
 
 /**
 * Generated by swagger-codegen

key/src/test/java/com/networknt/oauth/key/handler/Oauth2KeyKeyIdGetHandlerTest.java

@@ -15,7 +15,7 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import static com.networknt.client.oauth.TokenHelper.encodeCredentials;
+import static com.networknt.client.oauth.OauthHelper.encodeCredentials;
 
 /**
 * Generated by swagger-codegen