use local library source instead to correct some black-box issue for aliyuniot

lib/ArduinoJson/extras/tests/JsonVariant/CMakeLists.txt

@@ -0,0 +1,28 @@
+# ArduinoJson - arduinojson.org
+# Copyright Benoit Blanchon 2014-2020
+# MIT License
+
+add_executable(JsonVariantTests
+	add.cpp
+	as.cpp
+	clear.cpp
+	compare.cpp
+	containsKey.cpp
+	copy.cpp
+	createNested.cpp
+	is.cpp
+	isnull.cpp
+	memoryUsage.cpp
+	misc.cpp
+	nesting.cpp
+	or.cpp
+	overflow.cpp
+	remove.cpp
+	set.cpp
+	subscript.cpp
+	types.cpp
+	undefined.cpp
+)
+
+target_link_libraries(JsonVariantTests catch)
+add_test(JsonVariant JsonVariantTests)