Add codecov config #702

Job	Run time
Build Phar	40s
Functional - WP latest on PHP 7.3 with MySQL 8.0	6m 59s
Functional - WP 4.9 on PHP 7.2 with MySQL 5.6	6m 55s
Functional - WP trunk on PHP 7.4 with MySQL 5.7	5m 55s
Functional - WP trunk on PHP 8.5 with MySQL 8.0	4m 51s
Functional - WP trunk on PHP 8.5 with MySQL 5.7	5m 3s
Functional - WP latest on PHP 8.5 with MySQL 8.0	4m 47s
Functional - WP trunk on PHP 7.4 with MySQL 8.0	6m 42s
Functional - WP trunk on PHP 8.5 with MySQL 5.6	4m 57s
Functional - WP latest on PHP 7.4 with MySQL 8.0	6m 31s
Functional - WP trunk on PHP 7.4 with MySQL 5.6	6m 31s
Functional - WP latest on PHP 7.2 with MySQL 8.0	6m 51s
Deployment	13s
Build RPM package	0s
Build DEB package	0s
	1h 6m 55s

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