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_lexer.c

@@ -0,0 +1,47 @@
+#include "toy_lexer.h"
+#include "toy_console_colors.h"
+
+#include <stdio.h>
+#include <string.h>
+
+int main(void) {
+	{
+		//source code sample to operate on
+		char* source = "print null;";
+
+		//test the lexer
+		Toy_Lexer lexer;
+		Toy_bindLexer(&lexer, source);
+
+		//get each token
+		Toy_Token print = Toy_private_scanLexer(&lexer);
+		Toy_Token null = Toy_private_scanLexer(&lexer);
+		Toy_Token semi = Toy_private_scanLexer(&lexer);
+		Toy_Token eof = Toy_private_scanLexer(&lexer);
+
+		//test each token is correct
+		if (strncmp(print.lexeme, "print", print.length)) {
+			fprintf(stderr, TOY_CC_ERROR "ERROR: print lexeme is wrong: %s" TOY_CC_RESET, print.lexeme);
+			return -1;
+		}
+
+
+		if (strncmp(null.lexeme, "null", null.length)) {
+			fprintf(stderr, TOY_CC_ERROR "ERROR: null lexeme is wrong: %s" TOY_CC_RESET, null.lexeme);
+			return -1;
+		}
+
+		if (strncmp(semi.lexeme, ";", semi.length)) {
+			fprintf(stderr, TOY_CC_ERROR "ERROR: semicolon lexeme is wrong: %s" TOY_CC_RESET, semi.lexeme);
+			return -1;
+		}
+
+		if (eof.type != TOY_TOKEN_EOF) {
+			fprintf(stderr, TOY_CC_ERROR "ERROR: Failed to find EOF token" TOY_CC_RESET);
+			return -1;
+		}
+	}
+
+	printf(TOY_CC_NOTICE "All good\n" TOY_CC_RESET);
+	return 0;
+}