WIP: Retreived the unit tests (formerly test cases)

Some of these still work, others have just been dummied out for now.

Also added tests for console colors tool, and tweaked it to work
properly.

tests/units/test_ast.c

@@ -0,0 +1,9 @@
+#include "toy_ast.h"
+#include "toy_console_colors.h"
+
+#include <stdio.h>
+
+int main(void) {
+	printf(TOY_CC_WARN "Test not yet implemented: %s\n" TOY_CC_RESET, __FILE__);
+	return -1;
+}