CWL CommandLineTools are not currently visualized

[Common Workflow Language Viewer](https://view.commonwl.org/workflows) does not display the Graph of [user\_guide/1st\-tool\.cwl at gh\-pages · common\-workflow\-language/user\_guide](https://github.com/common-workflow-language/user_guide/blob/gh-pages/_includes/cwl/1st-tool.cwl)

## Description

I provide the following URL to `URL to workflow` field and push `Parse Workflow`

```
https://github.com/common-workflow-language/user_guide/blob/gh-pages/_includes/cwl/1st-tool.cwl
```

But there is not graph.

## Expected Behavior

Display the graph of [user\_guide/1st\-tool\.cwl at gh\-pages · common\-workflow\-language/user\_guide](https://github.com/common-workflow-language/user_guide/blob/gh-pages/_includes/cwl/1st-tool.cwl)

## Actual Behavior

Error

```
Error: The workflow could not be found within the repository
```

Looks like this

## Possible Fix

I hope more messages about the cause of error.

It is better to provide more information , ex. the error line of the file or URL is wrong or something about `Why this workflow is not parsed ?`

## Steps to Reproduce

1. Open https://view.commonwl.org
2. Fill `URL of workflow` with `https://github.com/common-workflow-language/user_guide/blob/gh-pages/_includes/cwl/1st-tool.cwl`
3. Push `Parse Workflow`

## Context

I want to see the graph of CWL files of CWL User guide .
At least I hope https://view.commonwl.org can parse any CWL file on https://github.com/common-workflow-language/
because view.commonwl.org is official tool.

## Your Environment

* Version used:
* Mac `62.0.3202.94 (Official Build) (64-bit)`