Maintenance (#259)

* Update CI config

* Update deprecated buffer usage

* Update dependencies

* Fix eslint error

* Update deprecated buffer usage

.travis.yml

@@ -1,9 +1,8 @@
-sudo: false
 language: node_js
 node_js:
+  - '12'
   - '10'
   - '8'
-  - '6'
 before_script:
   - npm install -g gulp
   - gulp lint

index.js

@@ -32,7 +32,6 @@ function addAssetsToStream(paths, files) {
     var self = this,
         gulpif = require('gulp-if'),
         concat = require('gulp-concat'),
-        isRelativeUrl = require('is-relative-url'),
         vfs = require('vinyl-fs'),
         extend = require('extend'),
         src,
@@ -52,7 +51,10 @@ function addAssetsToStream(paths, files) {
 
     // Get relative file paths and join with search paths to send to vinyl-fs
     globs = filepaths
-        .filter(isRelativeUrl)
+        .filter(function (url) {
+            // test if url is relative
+            return !/^(?:\w+:)?\/\//.test(url);
+        })
         .map(function (filepath) {
             paths.filepath = filepath;
 
@@ -76,7 +78,7 @@ function addAssetsToStream(paths, files) {
     });
 
     // option for newLine in gulp-concat
-    if (options.hasOwnProperty('newLine')) {
+    if (Object.prototype.hasOwnProperty.call(options, 'newLine')) {
         if (options.newLine === ';' && type === 'css') {
             options.newLine = null;
         }

lib/addHtmlToStream.js

@@ -6,7 +6,7 @@ module.exports = function (file, data) {
     var self = this;
 
     try {
-        file.contents = new Buffer(data);
+        file.contents = Buffer.from(data);
         self.push(file);
     } catch (err) {
         self.emit('error', new PluginError('gulp-useref', err));