[ArduinoJson] Update external library ArduinoJson.

Is needed to compile new ESP32 code.

lib/ArduinoJson/test/JsonArray/invalid.cpp

@@ -0,0 +1,34 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2018
+// MIT License
+
+#include <ArduinoJson.h>
+#include <catch.hpp>
+
+using namespace Catch::Matchers;
+
+TEST_CASE("JsonArray::invalid()") {
+  SECTION("SubscriptFails") {
+    REQUIRE_FALSE(JsonArray::invalid()[0].success());
+  }
+
+  SECTION("AddFails") {
+    JsonArray& array = JsonArray::invalid();
+    array.add(1);
+    REQUIRE(0 == array.size());
+  }
+
+  SECTION("CreateNestedArrayFails") {
+    REQUIRE_FALSE(JsonArray::invalid().createNestedArray().success());
+  }
+
+  SECTION("CreateNestedObjectFails") {
+    REQUIRE_FALSE(JsonArray::invalid().createNestedObject().success());
+  }
+
+  SECTION("PrintToWritesBrackets") {
+    char buffer[32];
+    JsonArray::invalid().printTo(buffer, sizeof(buffer));
+    REQUIRE_THAT(buffer, Equals("[]"));
+  }
+}