@return [LoadBalancer] Returns the load balancer with the given

  name.  This does not make a request, just returns a reference.

Creates and returns a load balancer. A load balancer requires:

• a unique name
• at least one availability zone
• at least one listener

An example that creates a load balancer in two availability zones with a single listener:

  load_balancer = elb.load_balancers.create('my-load-balancer',
    :availability_zones => %w(us-east-1a us-east-1b),
    :listeners => [{
      :port => 80,
      :protocol => :http,
      :instance_port => 80,
      :instance_protocol => :http,
    }])

@param [String] name The name of your load balancer. The name must

  be unique within your set of load balancers.

@param [Hash] options

@option options [required,Array] :availability_zones An array of

  one or more availability zones.  Values may be availability zone
  name strings, or {AWS::EC2::AvailabilityZone} objects.

@option options [required,Array] :listeners An array of load balancer

  listener options.  Each value must be an array with the following
  keys:

  +:port+
  +:protocol+
  +:instance_port+
  +:instance_protocol+

  Port values should be integers, and protocols should be symbols or
  strings (e.g. :http, or 'HTTP').  See {ListenerCollection#create}
  for more detailed description of each option.

@option options [String,IAM::ServerCertificate] :server_certificate (nil)

  The ARN string of an IAM::ServerCertifcate or an
  IAM::ServerCertificate object.  Reqruied for HTTPs listeners.