Added ManagementAPI token provider customization

Author: krrrr38

src/main/java/com/auth0/client/mgmt/ManagementAPI.java

@@ -401,7 +401,7 @@ public SelfServiceProfilesEntity selfServiceProfiles() {
      */
     public static class Builder {
         private final String domain;
-        private final String apiToken;
+        private TokenProvider tokenProvider
         private Auth0HttpClient httpClient = DefaultHttpClient.newBuilder().build();
 
         /**
@@ -411,7 +411,7 @@ public static class Builder {
          */
         public Builder(String domain, String apiToken) {
             this.domain = domain;
-            this.apiToken = apiToken;
+            this.tokenProvider = SimpleTokenProvider.create(apiToken);
         }
 
         /**
@@ -425,12 +425,22 @@ public Builder withHttpClient(Auth0HttpClient httpClient) {
             return this;
         }
 
+        /**
+         * Configure the token provider with an {@link TokenProvider}.
+         * @param tokenProvider the API Token provider to use when making requests.
+         * @return the builder instance.
+         */
+        public Builder withTokenProvider(TokenProvider tokenProvider) {
+            this.tokenProvider = tokenProvider;
+            return this;
+        }
+
         /**
          * Build a {@link ManagementAPI} instance using this builder's configuration.
          * @return the configured {@code ManagementAPI} instance.
          */
         public ManagementAPI build() {
-            return new ManagementAPI(domain, SimpleTokenProvider.create(apiToken), httpClient);
+            return new ManagementAPI(domain, tokenProvider, httpClient);
         }
     }
 }

src/test/java/com/auth0/client/mgmt/ManagementAPITest.java

@@ -68,7 +68,9 @@ public CompletableFuture<Auth0HttpResponse> sendRequestAsync(Auth0HttpRequest re
         };
 
         ManagementAPI api = ManagementAPI.newBuilder(DOMAIN, API_TOKEN)
-            .withHttpClient(httpClient).build();
+            .withHttpClient(httpClient)
+            .withTokenProvider(SimpleTokenProvider.create(API_TOKEN))
+            .build();
         assertThat(api, is(notNullValue()));
         assertThat(api.getHttpClient(), is(httpClient));
     }