Implement flexible fake backend

Change-Id: Icff0d3b8e1a82c7e459dfac6417f59502f0eb099
diff --git a/t/fixtures/response_server_fail.json b/t/fixtures/response_server_fail.json
new file mode 100644
index 0000000..51be2cb
--- /dev/null
+++ b/t/fixtures/response_server_fail.json
@@ -0,0 +1,4 @@
+{
+  "status" : 500,
+  "inline" : "Oooops"
+}