Fix some errors in pedantic mode for testing.h

test/testing.h

@@ -18,6 +18,7 @@
 
 #include <stdbool.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 
 #define MESSAGE(FILE, COLOUR, NAME, FORMAT, ...) \
@@ -38,7 +39,7 @@ struct Test
 };
 
 #define CREATE_TEST(NAME)      \
-  (struct Test)                \
+  (const struct Test)          \
   {                            \
     .name = #NAME, .src = NAME \
   }
@@ -73,7 +74,7 @@ static void byte_array_to_string(const byte_t *bytes, size_t size_bytes,
   size_t j = 1;
   for (size_t i = 0; i < size_bytes; ++i)
   {
-    char buffer[7];
+    char buffer[8];
     int k    = i == size_bytes - 1 ? 0 : 2;
     size_t n = 4 + k;