rb: Add benchmarking code for Thrift::NonblockingServer

You can override the server to test with the THRIFT_SERVER env var


git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@669007 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/lib/rb/benchmark/Benchmark.thrift b/lib/rb/benchmark/Benchmark.thrift
new file mode 100644
index 0000000..d0494cc
--- /dev/null
+++ b/lib/rb/benchmark/Benchmark.thrift
@@ -0,0 +1,5 @@
+namespace rb ThriftBenchmark
+
+service BenchmarkService {
+  i32 fibonacci(1:byte n)
+}