Describe the bug A clear and concise description of what the bug is.

Running black in the console generates a traceback.

To Reproduce Steps to reproduce the behavior:
Running black directly in the console gives me the following traceback.

Traceback (most recent call last):
  File "/Users/jonathan/projects/recorded/integrations/splunk/venv/bin/black", line 7, in <module>

Describe the bug

Duplicate imports are not removed with imports_granularity = "Item" turned on.

To Reproduce

test.rs

use std::env;
use std::env;

fn main() {
  println!("{:?}", env::var("TEST"));
}

.rustfmt.toml

unstable_features = true
edition = "2018"
imports_granularity = "Item"

Run rustfmt test.rs

Expected behavior

Duplicate `us

When I try to beautify the i get the following problem
TypeError: Cannot read property 'on' of undefined

I just installed beautify and uncrustify

https://gist.github.com/ODCA117/917affd6b11437517535a45350379820

We need to update our README.md file before the 1.0 release.