### What it does
Checks for usage of `!` or `!=` in an if condition with an
else branch.

### Why is this bad?
Negations reduce the readability of statements.

### Example
```
if !v.is_empty() {
    a()
} else {
    b()
}
```

Could be written:

```
if v.is_empty() {
    b()
} else {
    a()
}
```