adding Vulkan device creation, adding unit tests, adding few API function declarations

Tests/Vulkan/main.c

@@ -0,0 +1,41 @@
+#include <unity/unity.h>
+#include <Pulse.h>
+
+#include <stdbool.h>
+
+PulseBackend backend;
+
+extern void TestDeviceSetup();
+
+bool SetupPulse()
+{
+	backend = PulseLoadBackend(PULSE_BACKEND_VULKAN, PULSE_SHADER_FORMAT_SPIRV_BIT, PULSE_NO_DEBUG);
+	if(backend == PULSE_NULL_HANDLE)
+	{
+		fprintf(stderr, "Fatal Error: could not load Pulse using Vulkan due to %s", PulseVerbaliseErrorType(PulseGetLastErrorType()));
+		return false;
+	}
+	puts("Pulse loaded using Vulkan");
+	return true;
+}
+
+int RunUnitTests()
+{
+	UNITY_BEGIN();
+	RUN_TEST(TestDeviceSetup);
+	return UNITY_END();
+}
+
+void UnloadPulse()
+{
+	PulseUnloadBackend(backend);
+	puts("Pulse unloaded");
+}
+
+int main(void)
+{
+	SetupPulse();
+	int result = RunUnitTests();
+	UnloadPulse();
+	return result;
+}