Files archive path is relative to WP_CONTENT_DIR

[christianc1]

The files.tar.gz is written to ../.wpsnapshots/files.tar.gz, relative the value of WP_CONTENT_DIR. This is an issue when the wp-content directory isn't in ABSPATH common in "Composer Style" installations of Wordpress where the file structure resembles:

|- wp/
|-- wp-admin/
|-- wp-includes/
|- wp-content/
|-- themes/
|-- plugins/
|-composer.json

The files archive should be written to the same directory the database dump is located, which is aware --path option of the push command.