Revert "add volume support"

This reverts commit b8bb69f730.

Revert this for now, we will try a simpler non-object volume first

src/scheduler.js

@@ -173,7 +173,7 @@ function runTask(appId, taskName, callback) {
                 debug(`runTask: starting task ${taskName} of app ${app.fqdn} with cmd ${cmd}`);
 
                 // NOTE: if you change container name here, fix addons.js to return correct container names
-                docker.createSubcontainer(app, containerName, [ '/bin/sh', '-c', cmd ], function (error, container) {
+                docker.createSubcontainer(app, containerName, [ '/bin/sh', '-c', cmd ], { } /* options */, function (error, container) {
                     if (error) return callback(error);
 
                     docker.startContainer(container.id, callback);