fix(web): prevent Webpack from failing on linter warnings in development

[dgdavid]

Ensure Webpack doesn't crash on linter warnings during development, similar to how linter errors were handled in PR #2440, commit a7f9c45.

[dgdavid]

I faced

<e> [webpack-dev-middleware] HookWebpackError: [eslint] 
<e> /path/to/project/src/components/core/SelectableDataTable.tsx
<e>   330:5  warning  Expected property shorthand  object-shorthand
<e> 
<e> ✖ 2 problems (1 error, 1 warning)
<e>   0 errors and 1 warning potentially fixable with the `--fix` option.
<e> 
<e>     at makeWebpackError (//path/to/project/node_modules/webpack/lib/HookWebpackError.js:48:9)
<e>     at /path/to/project/node_modules/webpack/lib/Compilation.js:3364:12
<e>     at eval (eval at create (/path/to/project/node_modules/tapable/lib/HookCodeFactory.js:33:10), <anonymous>:31:1)
<e>     at /path/to/project/node_modules/webpack/lib/Compilation.js:594:27
<e>     at /path/to/project/node_modules/eslint-webpack-plugin/dist/index.js:157:11
<e> -- inner error --
<e> 
<e> caused by plugins in Compilation.hooks.processAssets
<e> 

when writing something like,

const sharedData = {
  columns: columns 
}

[coveralls]

coverage: 62.578%. remained the same
when pulling 755be10 on adjust-webpack-config
into 7d4339c on master.