title: Gulp-sass not finding variable in included files(s)?
body: <p>I have a _variables.scss file where a map is declared:</p>
  
  <pre><code>$chord1: (
    color1: rgb(0, 155, 223), 
    color2: rgb(114, 191, 68), 
    color3: rgb(207, 9, 137), 
    color4: rgb(62, 83, 164)
  );
  
  $chord: $chord1;
  </code></pre>
  
  <p>I have a second file. <code>_globals.scss</code> where I reference this:</p>
  
  <pre><code>.myClass { color: map-get($chord, color1); }
  </code></pre>
  
  <p>I have a the main scss file as app.scss, which @imports  them:</p>
  
  <pre><code>@import 'colors';
  @import 'globals';
  </code></pre>
  
  <p>However, gulp-sass throws an error <code>Error: invalid top-level expression</code> based on that map-get.</p>
  
  <p>I was using gulp-ruby-sass on one project and it worked.  However, in this project we are using gulp-sass 1.1.0.  My gulp task is:</p>
  
  <pre><code>gulp.task('styles', function () {
     return gulp.src('./app/assets/sass/app.scss')
     .pipe(plumber())
     .pipe(sass({ style: 'expanded' }))
     .pipe(gulp.dest('./app/assets/css'))
     .pipe(reload({stream: true}));
  });
  </code></pre>
  
  <p>Does this sort of thing just not work in gulp-sass?  Or am I doing something wrong?</p>