tests: runtime: Add out_logdna unit test

Signed-off-by: lecaros <lecaros@chronosphere.io>

Author: lecaros

tests/runtime/CMakeLists.txt

@@ -231,6 +231,7 @@ if(FLB_IN_LIB)
   FLB_RT_TEST(FLB_OUT_HTTP             "out_http.c")
   FLB_RT_TEST(FLB_OUT_KAFKA            "out_kafka.c")
   FLB_RT_TEST(FLB_OUT_LIB              "out_lib.c")
+  FLB_RT_TEST(FLB_OUT_LOGDNA           "out_logdna.c")
   FLB_RT_TEST(FLB_OUT_LOKI             "out_loki.c")
   FLB_RT_TEST(FLB_OUT_NULL             "out_null.c")
   FLB_RT_TEST(FLB_OUT_PLOT             "out_plot.c")