Use buffer directly (#16)

index.js

@@ -1,5 +1,5 @@
 'use strict';
-const execBuffer = require('exec-buffer');
+const execa = require('execa');
 const isJpg = require('is-jpg');
 const mozjpeg = require('mozjpeg');
 
@@ -14,7 +14,7 @@ module.exports = opts => buf => {
 		return Promise.resolve(buf);
 	}
 
-	const args = ['-outfile', execBuffer.output];
+	const args = [];
 
 	if (typeof opts.quality !== 'undefined') {
 		args.push('-quality', opts.quality);
@@ -76,12 +76,9 @@ module.exports = opts => buf => {
 		args.push('-maxmemory', opts.maxmemory);
 	}
 
-	args.push(execBuffer.input);
-
-	return execBuffer({
-		input: buf,
-		bin: mozjpeg,
-		args
+	return execa.stdout(mozjpeg, args, {
+		encoding: null,
+		input: buf
 	}).catch(err => {
 		err.message = err.stderr || err.message;
 		throw err;

package.json

@@ -41,7 +41,7 @@
     "optimize"
   ],
   "dependencies": {
-    "exec-buffer": "^3.0.0",
+    "execa": "^0.4.0",
     "is-jpg": "^1.0.0",
     "mozjpeg": "^4.0.0"
   },