feat: remove root option

BREAKING CHANGE: The root option was never documented, so it's very unlikely that this is actually a breaking change. However, since the option was removed, we need to flag this as breaking.

src/createWebpackLessPlugin.js

@@ -11,7 +11,7 @@ const trailingSlash = /[\\/]$/;
  * @param {string=} root
  * @returns {LessPlugin}
  */
-function createWebpackLessPlugin(loaderContext, root) {
+function createWebpackLessPlugin(loaderContext) {
   const resolve = pify(loaderContext.resolve.bind(loaderContext));
   const loadModule = pify(loaderContext.loadModule.bind(loaderContext));
 
@@ -22,7 +22,7 @@ function createWebpackLessPlugin(loaderContext, root) {
     }
 
     loadFile(filename, currentDirectory /* , options, environment */) { // eslint-disable-line class-methods-use-this
-      const moduleRequest = loaderUtils.urlToRequest(filename, root);
+      const moduleRequest = loaderUtils.urlToRequest(filename);
       // Less is giving us trailing slashes, but the context should have no trailing slash
       const context = currentDirectory.replace(trailingSlash, '');
       let resolvedFilename;

src/getOptions.js

@@ -19,7 +19,7 @@ function getOptions(loaderContext) {
   options.filename = loaderContext.resource;
 
   // It's safe to mutate the array now because it has already been cloned
-  options.plugins.push(createWebpackLessPlugin(loaderContext, options.root));
+  options.plugins.push(createWebpackLessPlugin(loaderContext));
 
   return options;
 }