[ArduinoJson] Update external library ArduinoJson.

Is needed to compile new ESP32 code.

lib/ArduinoJson/test/JsonObject/remove.cpp

@@ -0,0 +1,41 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2018
+// MIT License
+
+#include <ArduinoJson.h>
+#include <catch.hpp>
+#include <string>
+
+TEST_CASE("JsonObject::remove()") {
+  DynamicJsonBuffer jb;
+
+  SECTION("SizeDecreased_WhenValuesAreRemoved") {
+    JsonObject& obj = jb.createObject();
+    obj["hello"] = 1;
+
+    obj.remove("hello");
+
+    REQUIRE(0 == obj.size());
+  }
+
+  SECTION("SizeUntouched_WhenRemoveIsCalledWithAWrongKey") {
+    JsonObject& obj = jb.createObject();
+    obj["hello"] = 1;
+
+    obj.remove("world");
+
+    REQUIRE(1 == obj.size());
+  }
+
+  SECTION("RemoveByIterator") {
+    JsonObject& obj = jb.parseObject("{\"a\":0,\"b\":1,\"c\":2}");
+
+    for (JsonObject::iterator it = obj.begin(); it != obj.end(); ++it) {
+      if (it->value == 1) obj.remove(it);
+    }
+
+    std::string result;
+    obj.printTo(result);
+    REQUIRE("{\"a\":0,\"c\":2}" == result);
+  }
+}