Use JavaScript Standard Style

Introduce JavaScript Standard Style as project style rule,
and fixed all fail on backend code.

lib/logger.js

@@ -1,22 +1,22 @@
-var winston = require('winston');
-winston.emitErrs = true;
+var winston = require('winston')
+winston.emitErrs = true
 
 var logger = new winston.Logger({
-    transports: [
-        new winston.transports.Console({
-            level: 'debug',
-            handleExceptions: true,
-            json: false,
-            colorize: true,
-            timestamp: true
-        })
-    ],
-    exitOnError: false
-});
+  transports: [
+    new winston.transports.Console({
+      level: 'debug',
+      handleExceptions: true,
+      json: false,
+      colorize: true,
+      timestamp: true
+    })
+  ],
+  exitOnError: false
+})
 
-module.exports = logger;
+module.exports = logger
 module.exports.stream = {
-    write: function(message, encoding){
-        logger.info(message);
-    }
-};
+  write: function (message, encoding) {
+    logger.info(message)
+  }
+}