title: gulp not creating any files but finishes without any error
body: <p>I am trying to get all the files from bower_components and compressing them to on file like vendor.js and vendor.css. </p>
  
  <p>I get no error when I execute the command glup vendor-build. Is there something I am doing wrong? I got the script from another stackoverflow question. I tried searching more to make my scrip work but couldn't find anything. I know there is something wrong I am missing. </p>
  
  <p><strong>project dir structure</strong> </p>
  
  <p><a href="https://i.stack.imgur.com/CJqZN.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/CJqZN.png" alt="enter image description here"></a></p>
  
  <p><strong>gulpfile.js</strong></p>
  
  <pre><code>var gulp = require('gulp');
  
  // define plug-ins
  var flatten = require('gulp-flatten');
  var gulpFilter = require('gulp-filter');
  var uglify = require('gulp-uglify');
  var minifycss = require('gulp-minify-css');
  var rename = require('gulp-rename');
  var mainBowerFiles = require('main-bower-files');
  var concat = require('gulp-concat');
  
  // Define paths variables
  var dest_path =  'app/static';
  
  gulp.task('vendor-build', function() {
  
          var jsFilter = gulpFilter('*.js',  {restore: true});
          var cssFilter = gulpFilter('*.css',  {restore: true});
          var fontFilter = gulpFilter(['*.eot', '*.woff', '*.svg', '*.ttf']);
  
          return gulp.src(mainBowerFiles())
          .pipe(jsFilter)
          .pipe(concat('vendor.js'))
          .pipe(uglify())
          .pipe(rename({
              suffix: ".min"
          }))
          .pipe(gulp.dest(dest_path + '/js'))
          .pipe(jsFilter.restore)
          .pipe(cssFilter)
          .pipe(concat('vendor.css'))
          .pipe(minifycss())
          .pipe(rename({
              suffix: ".min"
          }))
          .pipe(gulp.dest(dest_path + '/css'))
          .pipe(cssFilter.restore)
          .pipe(fontFilter)
          .pipe(flatten())
          .pipe(gulp.dest(dest_path + '/fonts'));
  });
  </code></pre>