Is it possible to use bits instead of uin32_t inside raxNode?

```
typedef struct raxNode {
    uint32_t iskey:1;     /* Does this node contain a key? */
    uint32_t isnull:1;    /* Associated value is NULL (don't store it). */
    uint32_t iscompr:1;   /* Node is compressed. */
    uint32_t size:29;     /* Number of children, or compressed string len. */
```

e.g. `iskey` only have 1 or 0 here, right ?