Dev ludo

[post-l]

• new plugin system (2 types of plugins for now: notifier and testsuite)
• enhance json decode error
• slack: add verbose option and convert to plugin #5
• httpexect: add insecure option #9
• httpexpect: enhance json schema ref to other files #7
• move some logic from server to cmd/aragorn pkg
• command list: lists the testsuites with a text/tabwriter
• command watch: watches the test suites in the directories and execute them on create or update
• command run now takes a config file like the following one: aragorn run -config config.json -failfast -exec config.json:

  {
  "notifiers": {
  "slack": {
    "webhook": "https://hooks.slack.com/services/T/B/1",
    "verbose": true
  }
  },
  "suites": [
  {
    "path": "./test/shelob.suite.json",
    "runEvery": "1h",
    "failFast": true,
    "suite": {
      "base": {
        "url": "https://example.com",
        "insecure": true
      }
    }
  }
  ],
  "consoleLog": false
  }