[Rust] CI fails due to formatting errors

https://travis-ci.org/apache/arrow/jobs/485310770

 
Diff in /home/travis/build/apache/arrow/rust/arrow/src/csv/reader.rs at line 545:
Field::new("lng", DataType::Float64, false),
]);
 

• let file_with_headers = File::open("test/data/uk_cities_with_headers.csv").unwrap();
  + let file_with_headers =
  + File::open("test/data/uk_cities_with_headers.csv").unwrap();
  let file_without_headers = File::open("test/data/uk_cities.csv").unwrap();
  let both_files = file_with_headers
  .chain(Cursor::new("\n".to_string()))