[del] delate test files

build/coverage/_css/bootstrap.min.css

build/coverage/_css/custom.css

build/coverage/_css/nv.d3.min.css

build/coverage/_css/octicons.css

build/coverage/_css/style.css

build/coverage/_icons/file-code.svg

build/coverage/_icons/file-directory.svg

build/coverage/_js/bootstrap.min.js

build/coverage/_js/d3.min.js

build/coverage/_js/file.js

build/coverage/_js/jquery.min.js

build/coverage/_js/nv.d3.min.js

build/coverage/_js/popper.min.js

build/coverage/code.php.html

build/coverage/coverage.xml

build/coverage/dashboard.html

build/coverage/index.html

build/logs/checkstyle.xml

build/logs/junit.xml

build/logs/pmd.xml