Deprecated selector in `elastic-tabstops/styles/elastic-tabstops.less`

[brunocruzcoelho]

In elastic-tabstops/styles/elastic-tabstops.less:

Starting from Atom v1.13.0, the contents of atom-text-editor elements are no longer encapsulated within a shadow DOM boundary. This means you should stop using :host and ::shadow pseudo-selectors, and prepend all your syntax selectors with syntax--. To prevent breakage with existing style sheets, Atom will automatically upgrade the following selectors:

• atom-text-editor::shadow span.hard-tab => atom-text-editor.editor span.hard-tab

• atom-text-editor::shadow span.hard-tab.indent-guide:first-child => atom-text-editor.editor span.hard-tab.indent-guide:first-child

Automatic translation of selectors will be removed in a few release cycles to minimize startup time. Please, make sure to upgrade the above selectors as soon as possible.

[hax]

PR is welcome!