add available worker properties

[hd016]

according the rq documentation a worker have following properties:

• hostname - the host where this worker is run
• pid - worker’s process ID
• queues - queues on which this worker is listening for jobs
• state - possible states are suspended, started, busy and idle
• current_job - the job it’s currently executing (if any)
• last_heartbeat - the last time this worker was seen
• birth_date - time of worker’s instantiation
• successful_job_count - number of jobs finished successfully
• failed_job_count - number of failed jobs processed
• total_working_time - amount of time spent executing jobs, in seconds

these properties can also be used in the dashboard.

[ThomasThelen]

Steps I used to run

• virtualenv env
• source env/bin/activate
• pip install -r requirements.txt
• python setup.py develop
• docker run -d --name redis-stack-server -p 6379:6379 redis/redis-stack-server:latest
• rq-dashboard

No issue or problems when playing around in the UI. LGTM