add missing methods to checkout api root

Author: jenschude

commercetools/commercetools-sdk-java-checkout/src/main/java/com/commercetools/checkout/client/ProjectApiRoot.java

@@ -38,6 +38,17 @@ public ByProjectKeyTransactionsRequestBuilder transactions() {
         return with().transactions();
     }
 
+    @Override
+    public ByProjectKeyPaymentIntegrationsRequestBuilder paymentIntegrations() {
+        return with().paymentIntegrations();
+    }
+
+    @Override
+    public ByProjectKeyApplicationsRequestBuilder applications() {
+        return with().applications();
+    }
+
+
     public ByProjectKeyRequestBuilder withProjectKey(final String projectKey) {
         return ApiRoot.fromClient(apiHttpClient).withProjectKey(projectKey);
     }

commercetools/commercetools-sdk-java-checkout/src/main/java/com/commercetools/checkout/client/ProjectScopedApiRoot.java

@@ -7,4 +7,8 @@ public interface ProjectScopedApiRoot {
     ByProjectKeyTransactionsRequestBuilder transactions();
 
     ByProjectKeyPaymentIntentsRequestBuilder paymentIntents();
+
+    ByProjectKeyPaymentIntegrationsRequestBuilder paymentIntegrations();
+
+    public ByProjectKeyApplicationsRequestBuilder applications();
 }