Fix GHRepository#listWorkflows() and add a test

src/main/java/org/kohsuke/github/GHWorkflowsPage.java

@@ -0,0 +1,20 @@
+package org.kohsuke.github;
+
+/**
+ * Represents the one page of workflow result when listing workflows.
+ */
+class GHWorkflowsPage {
+    private int total_count;
+    private GHWorkflow[] workflows;
+
+    public int getTotalCount() {
+        return total_count;
+    }
+
+    GHWorkflow[] getWorkflows(GHRepository owner) {
+        for (GHWorkflow workflow : workflows) {
+            workflow.wrapUp(owner);
+        }
+        return workflows;
+    }
+}