Allow anonymous request

Author: Stran6

lib/jira.js

@@ -179,7 +179,7 @@ var JiraApi = exports.JiraApi = function(protocol, host, port, username, passwor
             token: oauth.access_token,
             token_secret: oauth.access_token_secret
           };
-        } else {
+        } else if(this.username && this.password) {
           options.auth = {
             'user': this.username,
             'pass': this.password