add alerts for siri requester

[OriHoch]

• expose an http page which return an OK status when there is SIRI snapshot in the storage for last minute
• add a monitoring service on this page which alerts when status is not OK

[OriHoch]

done:

• health check page:
  • https://open-bus-siri-requester.hasadna.org.il/health
  • checks seconds since last snapshot, if more then 120 seconds page returns status code 500
• added a statuscheck uptime check that monitors this page every 1 minute and alerts hasadna devops team

relevant code changes:

• https://github.com/hasadna/open-bus-siri-requester/pull/2
• https://github.com/hasadna/open-bus-pipelines/commit/708ccc619411a5cd1eed3d1bc294633c266c749c
• https://github.com/hasadna/hasadna-k8s/commit/d8ec5662094c66dfbce28e1d5e849166a3a6b58d