title: Can't find variable: require
body: <p>I use Angular with gulp. When i do a "gulp test", i got the error "ReferenceError: Can't find variable: require in /bower_components/gulp-ng-config/gulp-ng-config.js:3</p>
  
  <p>gulp/config.js</p>
  
  <pre><code>'use strict';
  
  var path = require('path'),
      gulp = require('gulp'),
      conf = require('./conf'),
      gulpNgConfig = require('gulp-ng-config');
  
  gulp.task('config', function () {
    gulp.src(path.join(conf.paths.src, '/app/config.json'))
      .pipe(gulpNgConfig('EnvConf', {
        environment: 'local'
      }))
      .pipe(gulp.dest(path.join(conf.paths.src, '/app/')));
  });
  
  gulp.task('config:build', function () {
    gulp.src(path.join(conf.paths.src, '/app/config.json'))
      .pipe(gulpNgConfig('EnvConf', {
        environment: 'production'
      }))
      .pipe(gulp.dest(path.join(conf.paths.src, '/app/')));
   });
  </code></pre>
  
  <p>gulp/server.js</p>
  
  <pre><code>gulp.task('serve', ['config','watch'], function() {
     browserSyncInit([path.join(conf.paths.tmp, '/serve'), conf.paths.src]);
  });
  
  gulp.task('serve:dist', ['config:build','build'], function() {
    browserSyncInit(conf.paths.dist);
  });
  
  gulp.task('serve:e2e', ['config','inject'], function() {
    browserSyncInit([conf.paths.tmp + '/serve', conf.paths.src], []);
  });
  
  gulp.task('serve:e2e-dist', ['config:build','build'], function() {
    browserSyncInit(conf.paths.dist, []);
  });
  </code></pre>
  
  <p>I try node v6.1.0 and v5.10.1.</p>