Upgrade all libraries. New canvas

.travis.yml

@@ -1,10 +1,8 @@
 language: node_js
 dist: trusty
 node_js:
-  - "4"
-  - "6"
-  - "7"
-  - "8"
+  - node
+  - lts/*
 addons:
   apt:
     sources:

lib/GIFEncoder.js

@@ -17,7 +17,7 @@ function ByteArray() {
 }
 
 ByteArray.prototype.getData = function() {
-  return new Buffer(this.data);
+  return new Buffer.from(this.data);
 };
 
 ByteArray.prototype.writeByte = function(val) {
@@ -113,7 +113,7 @@ GIFEncoder.prototype.emit = function() {
   if (this.readStreams.length === 0) return;
   if (this.out.data.length) {
     this.readStreams.forEach(function (rs) {
-      rs.push(new Buffer(self.out.data));
+      rs.push(Buffer.from(self.out.data));
     });
     this.out.data = [];
   }