Split unit test into several executables

test/JsonVariant/CMakeLists.txt

@@ -0,0 +1,21 @@
+# Copyright Benoit Blanchon 2014-2017
+# MIT License
+# 
+# Arduino JSON library
+# https://bblanchon.github.io/ArduinoJson/
+# If you like this project, please add a star!
+
+add_executable(JsonVariantTests 
+	as.cpp
+	compare.cpp
+	copy.cpp
+	is.cpp
+	printTo.cpp
+	set_get.cpp
+	subscript.cpp
+	success.cpp
+	undefined.cpp
+)
+
+target_link_libraries(JsonVariantTests gtest)
+add_test(JsonVariant JsonVariantTests)