Fails if using the new Azure Pipelines based connection endpoint

Nobody has claimed this yet.

## Bug Report

Azure DevOps has a new way of creating service endpoints - the Azure Pipelines app from the GitHub marketplace. When using that endpoint with the task, I get the following error. I suspect it needs to check for a different field for the access token/PAT?

```

2018-09-10T19:13:39.7462851Z ##[error]An error occured, log returned:
An error occured, log returned:
Error: missing required options: token
2018-09-10T19:13:39.7474073Z Finish draft release
```
To repro:

Go the GitHub marketplace and look for the Azure Pipelines app under the CI category. Follow the wizard to connect it to your VSTS account/project. It creates a new service endpoint with the GitHub org name.

Use that endpoint in a build/release pipeline with this task.

*Before opening an issue please [read this](https://github.com/marceloavf/github-tools-vsts/wiki/How-to-Report-an-issue).*

**Describe the bug**

*A clear and concise description of what the bug is.*

**To Reproduce**

1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error

```shell
MANDATORY FOR BUGS: Insert debug trace
```

*In order to allow us to quickly reproduce you issue please include a link to a reproduction repository.*

**Expected behavior**

*A clear and concise description of what you expected to happen..*

**Enviroment**

* Service: [e.g. VSTS, TFS]
* Agent: [e.g. Hosted, Custom]
* OS: [e.g. OSX 10.13.4, Windows 10]
* Node/npm version: [e.g. Node 8/npm 5]

**Additional context/Screenshots**
Add any other context about the problem here. If applicable, add screenshots to help explain.

Start at the task's service-endpoint handling and reproduce with an Azure Pipelines app endpoint connected to a VSTS project. Compare the endpoint data used by the task with the failing token lookup; done means the task accepts that endpoint and no longer reports “missing required options: token”.

Written by the indexing model from the issue text.