Feature/zephyr ztest (#118)

* Leverage (older) embedded unit tests into external unit tests build upon copy of Zephyr's ztest library and CMake.

* Expand top-level CMake build to run external unit tests.

* Expand Zephyr module extension to run external unit tests via west or sanitycheck.

Co-authored-by: Gregory Shue <gregory.shue@legrand.us>

test/bacnet/lso/src/main.c

@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2020 Legrand North America, LLC.
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+/* @file
+ * @brief test BACnet integer encode/decode APIs
+ */
+
+#include <ztest.h>
+#include <bacnet/lso.h>
+
+/**
+ * @addtogroup bacnet_tests
+ * @{
+ */
+
+/**
+ * @brief Test
+ */
+static void testLSO(void)
+{
+    uint8_t apdu[1000];
+    int len;
+
+    BACNET_LSO_DATA data;
+    BACNET_LSO_DATA rxdata;
+
+    memset(&rxdata, 0, sizeof(rxdata));
+
+    characterstring_init_ansi(&data.requestingSrc, "foobar");
+    data.operation = LIFE_SAFETY_OP_RESET;
+    data.processId = 0x1234;
+    data.use_target = true;
+    data.targetObject.instance = 0x1000;
+    data.targetObject.type = OBJECT_BINARY_INPUT;
+
+    len = lso_encode_apdu(apdu, 100, &data);
+
+    lso_decode_service_request(&apdu[4], len, &rxdata);
+
+    zassert_equal(data.operation, rxdata.operation, NULL);
+    zassert_equal(data.processId, rxdata.processId, NULL);
+    zassert_equal(data.use_target, rxdata.use_target, NULL);
+    zassert_equal(data.targetObject.instance, rxdata.targetObject.instance, NULL);
+    zassert_equal(data.targetObject.type, rxdata.targetObject.type, NULL);
+    zassert_equal(
+        memcmp(data.requestingSrc.value, rxdata.requestingSrc.value,
+            rxdata.requestingSrc.length), 0, NULL);
+}
+/**
+ * @}
+ */
+
+
+void test_main(void)
+{
+    ztest_test_suite(lso_tests,
+     ztest_unit_test(testLSO)
+     );
+
+    ztest_run_test_suite(lso_tests);
+}