code: function start(callback) {
    let handle = {close(){server.close()}}
    check(function _check(err, inUse) {
      if (err) throw err
      if (inUse) {
        server = {close(){}}
        init(callback)
      }
      else {
        server = dynalite({
          createTableMs: 0
        }).listen(5000, function _server(err) {
          if (err) {
            // if we err then the db has been started elsewhere..
            // just try to continue
            console.log(err)
          }
          init(callback)
        })
      }
    })
    return handle
  }
docs: starts an in-memory dynalite dynamodb server
  
  - automatically creates any tables or indexes defined by the arcfile
  - also creates a local session table