chore: fix linting problems

src/gitdown.js

@@ -8,9 +8,9 @@ const _ = require('lodash');
 const MarkdownContents = require('markdown-contents');
 const marked = require('marked');
 const StackTrace = require('stack-trace');
-const contents = require('./helpers/contents.js');
-const gitinfo = require('./helpers/gitinfo.js');
-const Parser = require('./parser.js');
+const contents = require('./helpers/contents');
+const gitinfo = require('./helpers/gitinfo');
+const Parser = require('./parser');
 
 /**
  * @param {string} input Gitdown flavored markdown.

src/index.js

@@ -1,5 +1,5 @@
-const Gitdown = require('./gitdown.js');
+const Gitdown = require('./gitdown');
 
-Gitdown.Parser = require('./parser.js');
+Gitdown.Parser = require('./parser');
 
 module.exports = Gitdown;

src/parser.js

@@ -2,7 +2,7 @@ const Path = require('path');
 const Promise = require('bluebird');
 const glob = require('glob');
 const _ = require('lodash');
-const Locator = require('./locator.js');
+const Locator = require('./locator');
 
 /**
  * Parser is responsible for matching all of the instances of the Gitdown JSON and invoking