Move to imports

Move to the `import` syntax for bringing in the dependencies. Note that
since Atom calls the service provider function on package activation this
doesn't make a big difference on performance.

Author: Arcanemagus

lib/main.js

@@ -1,13 +1,14 @@
 'use babel';
 
+import * as helpers from 'atom-linter';
+import { extname } from 'path';
+
 export default {
   activate: () => {
     require('atom-package-deps').install('linter-ruby');
   },
 
   provideLinter: () => {
-    const helpers = require('atom-linter');
-    const Path = require('path');
     const regex = /.+:(\d+):\s*(.+?)[,:]\s(.+)/;
     return {
       name: 'Ruby',
@@ -18,7 +19,7 @@ export default {
         const command = atom.config.get('linter-ruby.rubyExecutablePath');
         const ignored = atom.config.get('linter-ruby.ignoredExtensions');
         const filePath = activeEditor.getPath();
-        const fileExtension = Path.extname(filePath).substr(1);
+        const fileExtension = extname(filePath).substr(1);
 
         if (ignored.includes(fileExtension)) {
           return [];