THRIFT-2729: C++ - .clang-format created and applied

Client: C++
Patch: Konrad Grochowski

make style command added
diff --git a/test/cpp/Makefile.am b/test/cpp/Makefile.am
index 33e71a3..b072440 100755
--- a/test/cpp/Makefile.am
+++ b/test/cpp/Makefile.am
@@ -104,6 +104,9 @@
 clean-local:
 	$(RM) -r gen-cpp
 
+style-local:
+	$(CPPSTYLE_CMD)
+
 EXTRA_DIST = \
 	src/TestClient.cpp \
 	src/TestServer.cpp \