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

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

@@ -0,0 +1,14 @@
+# ArduinoJson - arduinojson.org
+# Copyright Benoit Blanchon 2014-2020
+# MIT License
+
+add_executable(MemoryPoolTests 
+	allocVariant.cpp
+	allocString.cpp
+	clear.cpp
+	size.cpp
+	StringBuilder.cpp
+)
+
+target_link_libraries(MemoryPoolTests catch)
+add_test(MemoryPool MemoryPoolTests)