Unit test inclusion for new file

tests/unit_test/test_keep_alive.c

+/* ================ Includes ===================== */
+#include <criterion/criterion.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <linux/i2c-dev.h>
+#include <fcntl.h>
+#include <string.h>
+#include <open62541/plugin/log_stdout.h>
+
+#include "../../coupler/opc-ua-server/mod_io_i2c.h"
+#include "../../coupler/opc-ua-server/keep_alive.h"
+
+
+/* ================ Function Tests =============== */
+
+// ############# get I2C Slave List Length ##############
+
+Test(keepalive, gotoSafeMode) {
+    int result = 1;
+
+    gotoSafeMode();
+
+    cr_expect_eq(I2C_VIRTUAL_MODE, result);
+}
+
+// ############# Set Relay State (only virtual mode) ##############
+
+Test(keepalive, gotoNormalMode) {
+    int result = 0;
+
+    gotoNormalMode();
+
+    cr_expect_eq(I2C_VIRTUAL_MODE, result);
+}
\ No newline at end of file