### What it does
Checking for imports with single component use path.

### Why is this bad?
Import with single component use path such as `use cratename;`
is not necessary, and thus should be removed.

### Example
```
use regex;

fn main() {
    regex::Regex::new(r"^\d{4}-\d{2}-\d{2}$").unwrap();
}
```
Better as
```
fn main() {
    regex::Regex::new(r"^\d{4}-\d{2}-\d{2}$").unwrap();
}
```