Secure HTTP call support

[dileepbapat]

Is your feature request related to a problem? Please describe.
The current HTTP mode is not working with HTTPS for callout in the steps.

Steps to reproduce

POST http://localhost:8080/workflow
Content-Type: application/json

{
  "name": "sometestv2",
  "description": "test",
  "steps": [
    {
      "name": "get_detail",
      "mode": "HTTP",
      "val": {
        "method": "GET",
        "url": "https://api.github.com/users/dileepbapat"
      }
    }
  ]
}

POST http://localhost:8080/serviceRequest/sometestv2

{}

Describe the solution you'd like
Can be different mode HTTPS, but I would say HTTP and HTTPS modes are switched without a change in underlying request semantic. So based on URL scheme https can be supported with existing HTTP mode itself.

[sivachandran]

@dileepbapat @priyaaank Is it still valid? The demo workflow steps call https://run.mocky.io/... (HTTPS) URLs and they are working fine.