Fixes failing collection tests

This fixes one of the problems from issue #89 which is tests from rules.collections failing.

Basically any rewrite in a vector is not being applied correctly, for example:

```
(assoc data foo (inc (foo bar))
```

We end up with:

```
(update-in data [?key] inc)
```

Instead of:

```
(update-in data [foo] inc)
```

By converting all vector literals into an s-expression of form `(:kibit.rules/vector ...)` we can apply the rewrites and then go back to the square-bracket notation.

There maybe a more trivial way, but this seems to work and all `rule.collections` tests pass now.