Add an option/property in a job to rerun this job if it failed

[BigNuoLi]

Add an new option in the infrabox job options list to rerun this job if it failed.

Here is an example infrabox.json file,

{ "version": 1, "jobs": [{ "type": "docker", "name": "retest", "resources": { "limits": { "cpu": 1, "memory": 1024 } }, "build_only": false, "docker_file": "Dockerfile", "retry": "1" }] }

when "retry" = 0, infrabox works as before. when "retry" = N, infrabox will rerun the job "retest" N times if the prior execution of this job failed.