fix: don't create additional chunk for sprite

Closes: #364

lib/plugin.js

@@ -1,7 +1,6 @@
 /* eslint-disable import/no-extraneous-dependencies */
 const merge = require('deepmerge');
 const Promise = require('bluebird');
-const Chunk = require('webpack/lib/Chunk');
 const SVGCompiler = require('svg-baker');
 const spriteFactory = require('svg-baker/lib/sprite-factory');
 const Sprite = require('svg-baker/lib/sprite');
@@ -163,10 +162,6 @@ class SVGSpritePlugin {
       })
         .then((sprite) => {
           const content = sprite.render();
-          const chunkName = filename.replace(/\.svg$/, '');
-          const chunk = new Chunk(chunkName);
-          chunk.ids = [];
-          chunk.files.push(filename);
           const filenamePrefix = this.rules.publicPath
             ? this.rules.publicPath.replace(/^\//, '')
             : '';
@@ -175,8 +170,6 @@ class SVGSpritePlugin {
             source() { return content; },
             size() { return content.length; }
           };
-
-          compilation.chunks.push(chunk);
         });
     });
   }