Font location on Ubuntu servers are not correct

[jasverix]

This is:

- [ x ] a bug report
- [ ] a feature request
- [ ] **not** a usage question (ask them on https://stackoverflow.com/questions/tagged/phpspreadsheet or https://gitter.im/PHPOffice/PhpSpreadsheet)

What is the expected behavior?

When using Excel file with i.e. Calibri, it should find the installed font, when it is installed on /usr/share/fonts/truetype/vista/calibri.ttf. All truetype fonts installed on our server at least, are installed grouped by directories.

What is the current behavior?

It cannot find the font. And the reason is pretty obvious. $fontFile = self::$trueTypeFontPath . $fontFile;. It makes no effort to look in sub-directories.

What are the steps to reproduce?

Set true-type font directory to /usr/share/fonts/truetype/ as the documentation states, and try to use it.

What features do you think are causing the issue

• [ ] Reader
• [ ] Writer
• [ ] Styles
• [ ] Data Validations
• [ ] Formula Calulations
• [ ] Charts
• [ ] AutoFilter
• [ ] Form Elements
• [ x ] Fonts

[jasverix]

I may submit a pull request on this later, but I just wanted to register the issue for now.