Add missing trycatch (#171)

# Conflicts:
#	src/js_stream.cc

Author: victorgomes

src/js_stream.cc

@@ -163,6 +163,7 @@ void JSStream::Finish(const FunctionCallbackInfo<Value>& args) {
 
 
 void JSStream::ReadBuffer(const FunctionCallbackInfo<Value>& args) {
+  v8::TryCatch try_catch(args.GetIsolate());
   JSStream* wrap;
   ASSIGN_OR_RETURN_UNWRAP(&wrap, args.This());