Added comment to clearify why istanbul should be required after the istanbul-threshold-checker.

Author: jvanoostveen

index.js

@@ -3,6 +3,8 @@
 var through = require('through2').obj;
 var path = require('path');
 var checker = require('istanbul-threshold-checker');
+// Make sure istanbul is `require`d after the istanbul-threshold-checker to use the istanbul version 
+// defined in this package.json instead of the one defined in istanbul-threshold-checker.
 var istanbul = require('istanbul');
 var gutil = require('gulp-util');
 var _ = require('lodash');