Proposal: GraphQL runner about runn HOT 2 CLOSED

desc: cg
vars:
  name: testGroup
  code: null
runners:
  req: ${RUNNER_HOST:-http://localhost:8000}/query
steps:
  login:
    include:
      path: steps/login.yaml

  createGroup:
    req:
      /:
        post:
          headers:
            authorization: "bearer {{ steps.login.token }}"
          body:
            application/json:
              query: |
                mutation(
                  $name: String!
                  $code: String
                ) {
                  createGroup(input: {
                    name: $name,
                    code: $code
                  }) {
                    id
                  }
                }
              variables:
                name: "{{ vars.name }}"
                code: "{{ vars.code }}" # here can pass `null` that I have wanted to.