Add tests for page hook

test/node_modules/gitbook-plugin-test-deprecated/index.js

@@ -0,0 +1,8 @@
+module.exports = {
+    hooks: {
+        page: function(page) {
+            page.sections[0].content = 'Hello (sections) ' + page.content;
+            return page;
+        }
+    }
+};

test/node_modules/gitbook-plugin-test-deprecated/package.json

@@ -0,0 +1,7 @@
+{
+    "name": "gitbook-plugin-test-deprecated",
+    "version": "1.0.0",
+    "engines": {
+        "gitbook": "*"
+    }
+}