refactor(authorization): refactor to more clear method name

Author: Jiankai Zheng

src/main/java/spotify/api/authorization/AuthorizationPKCERequestToken.java

@@ -25,7 +25,7 @@ public AuthorizationPKCERequestToken() {
      * @param redirectUri the redirect uri supplied when requesting the authorization code
      * @return an object containing values like the access and refresh token
      */
-    public AuthorizationCodeFlowTokenResponse getAccessAndRefreshToken(String clientId, String code, String redirectUri, String codeVerifier) {
+    public AuthorizationCodeFlowTokenResponse getAuthorizationCodeToken(String clientId, String code, String redirectUri, String codeVerifier) {
         logger.trace("Constructing HTTP call to fetch an access and refresh token.");
         final Call<AuthorizationCodeFlowTokenResponse> httpCall = authorizationCodeFlowService
                 .getAccessAndRefreshTokenPKCE(

src/main/java/spotify/api/authorization/AuthorizationRequestToken.java

@@ -35,7 +35,7 @@ public AuthorizationRequestToken() {
      * @param redirectUri  the redirect uri supplied when requesting the authorization code
      * @return an object containing values like the access and refresh token
      */
-    public AuthorizationCodeFlowTokenResponse getAccessAndRefreshToken(String clientId, String clientSecret, String code, String redirectUri) {
+    public AuthorizationCodeFlowTokenResponse getAuthorizationCodeToken(String clientId, String clientSecret, String code, String redirectUri) {
         logger.trace("Encoding client id and secret to base 64.");
         final String base64EncodedBasicAuth = Credentials.basic(clientId, clientSecret);
 

src/main/java/spotify/api/authorization/ClientCredentialsFlow.java

@@ -43,7 +43,7 @@ public ClientCredentialsFlow() {
      * @param clientSecret secret of the client
      * @return an object containing the access token
      */
-    public ClientCredentialsFlowTokenResponse getAccessToken(String clientId, String clientSecret) {
+    public ClientCredentialsFlowTokenResponse getClientCredentialToken(String clientId, String clientSecret) {
         logger.trace("Encoding client id and secret to base 64.");
         final String base64EncodedBasicAuth = Credentials.basic(clientId, clientSecret);