Add compression to getInstanceName

Set the compression header when doing requests in getInstanceName.

lib/clusterTools/getInstanceName.js

@@ -8,7 +8,7 @@ module.exports = function(config){
 			return new Promise((resolve, reject) => {
 				let instance = instances[instanceID];
 				if(!instance){
-					needle.get(config.masterURL + '/api/slaves', (err, response) => {
+					needle.get(config.masterURL + '/api/slaves', { compressed: true }, (err, response) => {
 						if(err || response.statusCode != 200) {
 							console.log("Unable to get JSON master/api/slaves, master might be unaccessible");
 						} else if (response && response.body) {