Upgrade to webpack v4

[rafaelverger]

FIX #2

• Plugin clean-webpack-plugin was removed
• All dependencies were upgraded to lastest versions
• Test routine ✅

[rafaelverger]

➜  base64-inline-loader git:(upgrade_webpack4) npm test

> base64-inline-loader@1.1.0 test /Users/rafaelverger/git-projects/base64-inline-loader
> npm run webpack && npm run mocha


> base64-inline-loader@1.1.0 webpack /Users/rafaelverger/git-projects/base64-inline-loader
> webpack --mode production --progress --display-error-details --config tests/config.js

  0% [0] compiling(node:2340) DeprecationWarning: Tapable.apply is deprecated. Call apply on the plugin directly instead
  0% [0] Hash: a2830f0b486c6f8384c1
Version: webpack 4.1.0
Child
    Hash: a2830f0b486c6f8384c1
    Time: 769ms
    Built at: 3/5/2018 8:10:52 PM
            Asset       Size  Chunks             Chunk Names
    material.woff   56.3 KiB          [emitted]
        index.css  928 bytes    0, 0  [emitted]  main, main
    Entrypoint main = index.css index.css
       [0] ./tests/fixtures/index.css 110 bytes [built]
    Child extract-text-webpack-plugin node_modules/extract-text-webpack-plugin/dist node_modules/css-loader/index.js!tests/fixtures/index.css:
                Asset      Size  Chunks             Chunk Names
        material.woff  56.3 KiB          [emitted]
        Entrypoint undefined = extract-text-webpack-plugin-output-filename
           [0] ./tests/fixtures/icons/16x16.png 847 bytes {0} [built]
           [1] ./tests/fixtures/fonts/material.woff 59 bytes {0} [built]
           [4] ./node_modules/css-loader!./tests/fixtures/index.css 425 bytes {0} [built]
            + 2 hidden modules

> base64-inline-loader@1.1.0 mocha /Users/rafaelverger/git-projects/base64-inline-loader
> mocha --full-trace --ui tdd index.js tests/index.js



  Default test
    ✓ Convert files


  1 passing (10ms)

[rafaelverger]

@monolithed can u check this?

[monolithed]

@rafaelverger, thanks for your PR. base64-inline-loader@1.1.1