Write a Rodan job package

The job packages reside in the folder /rodan/jobs/. A job vendor provides its directory under this folder, where multiple Rodan jobs are defined. A job vendor can define the resource types that are required for its jobs as well.

Describe a Rodan job

A Rodan job is defined by a class that inherits rodan.jobs.base.RodanTask. The class should define the following attributes as its description:

attribute	description
name	string a unique name within all the jobs provided by the vendor.
author	string the author of the job.
description	string
settings	[JSON Schema](http://json-schema.org/)1 the validation schema that describes the requirements of the job settings.
enabled	boolean
category	string
interactive	boolean indicates whether the job will pause at some point and wait for manual input.2
input_port_types	list of Python dictionary
output_port_types	list of Python dictionary

1 - At present, Rodan only supports a JSON object as the topmost structure of settings.

2 - It is only informative for the users. It does not affect whether the job will pause. The behaviour of the job is determined by the return value of its execution code.

For input_port_types and output_port_types, the following keys should be defined:

key	description
name	string
resource_types	list of string OR lambda: string -> boolean describes all possible resource MIME-types. If provided with a lambda function, Rodan will automatically filter the matched resource types in its registry.
minimum	number minimum requirement of the job. 0 indicates no minimum requirement.
maximum	number maximum requirement of the job. 0 indicates no maximum requirement.

Describe Resource Types

A vendor can describe the required resource types through the file resource_types.yaml. It is a list of mappings, which include:

name	description
mimetype	string
description	(optional) string
extension	(optional) string the suggested extension of this resource type.