add arduinoJson

lib/ArduinoJson/extras/conf_test/esp8266.cpp

@@ -0,0 +1,16 @@
+#include <ArduinoJson.h>
+
+static_assert(ARDUINOJSON_USE_LONG_LONG == 1, "ARDUINOJSON_USE_LONG_LONG");
+
+static_assert(ARDUINOJSON_SLOT_OFFSET_SIZE == 2,
+              "ARDUINOJSON_SLOT_OFFSET_SIZE");
+
+static_assert(ARDUINOJSON_LITTLE_ENDIAN == 1, "ARDUINOJSON_LITTLE_ENDIAN");
+
+static_assert(ARDUINOJSON_USE_DOUBLE == 1, "ARDUINOJSON_USE_DOUBLE");
+
+static_assert(sizeof(ARDUINOJSON_NAMESPACE::VariantSlot) == 16,
+              "sizeof(VariantSlot)");
+
+void setup() {}
+void loop() {}