Expanding YAML hash with link text fails

```
JekyllSupport::HRefTag expands YAML hash with link text
     Failure/Error: expect(href.link).to   eq('https://github.com/diasks2/confidential_info_redactor')

       expected: #<Encoding:UTF-8> "https://github.com/diasks2/confidential_info_redactor"
            got: #<Encoding:ASCII-8BIT> "{{github}}/diasks2/confidential_info_redactor"
```