ci: run pio test directory

code/test/unit/basic/basic.cpp

@@ -0,0 +1,16 @@
+#include <unity.h>
+#include <Arduino.h>
+
+// Ensure build system works
+// ref: https://github.com/bxparks/UnixHostDuino/pull/6
+
+void test_linkage() {
+    pinMode(0, INPUT);
+    pinMode(0, OUTPUT);
+}
+
+int main(int argc, char** argv) {
+    UNITY_BEGIN();
+	RUN_TEST(test_linkage);
+    UNITY_END();
+}