[FIX] change eslint version to 2.1

package.json

@@ -43,7 +43,7 @@
     "coveralls": "^2.10.0",
     "doctoc": "^0.15.0",
     "ejs": "^2.3.4",
-    "eslint": "^1.3.0",
+    "eslint": "^2.1.0",
     "eventemitter2": "^0.4.14",
     "flow-bin": "^0.14",
     "gulp": "^3.8.10",

src/common/connection.js

@@ -1,4 +1,3 @@
-'use strict';
 const _ = require('lodash');
 const {EventEmitter} = require('events');
 const WebSocket = require('ws');

test/connection-test.js

@@ -1,5 +1,4 @@
 /* eslint-disable max-nested-callbacks */
-'use strict';
 
 const _ = require('lodash');
 const net = require('net');