Added gitbook version for building

olasitarska · olasitarska · commit b75678dfe000 · 2015-03-28T16:15:46.000-04:00
diff --git a/book.json b/book.json
@@ -16,5 +16,7 @@
         "richquotes" : {
             "todos" : true
         }
-    }
+    },
+
+    "gitbook": "1.5.0"
 }
