use modern-syslog instead of node-syslog, because node-syslog is not supported anymore

lib/logger.js

@@ -8,7 +8,7 @@ var Logger = function (config) {
     this.util = require('util');
   } else {
     if (this.backend == 'syslog') {
-      this.util = require('node-syslog');
+      this.util = require('modern-syslog');
       this.util.init(config.application || 'statsd', this.util.LOG_PID | this.util.LOG_ODELAY, this.util.LOG_LOCAL0);
     } else {
       throw "Logger: Should be 'stdout' or 'syslog'.";

package.json

@@ -23,7 +23,7 @@
     "temp": "0.4.x"
   },
   "optionalDependencies": {
-    "node-syslog":"1.2.0",
+    "modern-syslog":"1.1.2",
     "hashring":"3.2.0",
     "winser": "=0.1.6"
   },