Implement flexible fake backend

Change-Id: Icff0d3b8e1a82c7e459dfac6417f59502f0eb099
diff --git a/t/fixtures/response_no_query.json b/t/fixtures/response_no_query.json
new file mode 100644
index 0000000..5f75741
--- /dev/null
+++ b/t/fixtures/response_no_query.json
@@ -0,0 +1,9 @@
+{
+  "status" : 400,
+  "@context" : "http://korap.ids-mannheim.de/ns/koral/0.3/context.jsonld",
+  "errors":[
+    [
+      301,"You did not specify a query!"
+    ]
+  ]
+}