Close GH-3: fix issue allowing leading zeroes in major, minor and pat…

…ch. Fixes #2

index.js

@@ -1,4 +1,4 @@
 'use strict';
 module.exports = function () {
- return /v?\d+\.\d+\.\d+(?:-[\da-z\-]+(?:\.[\da-z\-]+)*)?(?:\+[\da-z\-]+(?:\.[\da-z\-]+)*)?/ig;
+ return /\bv?(?:0|[1-9][0-9]*)\.(?:0|[1-9][0-9]*)\.(?:0|[1-9][0-9]*)(?:-[\da-z\-]+(?:\.[\da-z\-]+)*)?(?:\+[\da-z\-]+(?:\.[\da-z\-]+)*)?\b/ig;
 };