Remove extern crate

Manishearth · web-flow · commit 4390d482cbac · 2019-06-20T07:19:17.000-07:00
Fixes #58
diff --git a/README.md b/README.md
@@ -6,8 +6,6 @@ to the [Unicode Standard Annex #29](http://www.unicode.org/reports/tr29/) rules.
 [Documentation](https://unicode-rs.github.io/unicode-segmentation/unicode_segmentation/index.html)
 
 ```rust
-extern crate unicode_segmentation;
-
 use unicode_segmentation::UnicodeSegmentation;
 
 fn main() {
