Create more default tests like test_url:
  dns query
  check all disks usage by config.check_disk_usage = true, or for custom list
  check all mounts by config.check_mounts = true, or for custom list
  open ports, local or remote
  monitor number output and alerts or takes action when new output is too far from average (create test config option for timeframe of average calculation, with default of 24h)
  ping
  check blacklists for domain or IP
  check open relay
  config.check_mem = true, to check memory and swap
  config.check_load = true, for load average

Add option when using test_url:
  method: get or head

Multithread for parallel checks

flexibilize period, currently hardcoded to 60s

Lockfile for process

lock for sys tests

remove slack-ruby-client from Gemfile. If it is set in .yml and is not available, send a error to log with instructions to install.

adjusts dependencies verions