Update .gitattributes (#792)

Updated list of useless files deployed on servers or embedded copies.

Author: williamdes

.gitattributes

@@ -4,11 +4,16 @@
 /.editorconfig export-ignore
 /.gitattributes export-ignore
 /.gitignore export-ignore
-/.php_cs export-ignore
+/.php-cs-fixer.php export-ignore
 /.scrutinizer.yml export-ignore
-/.travis.yml export-ignore
+/.github export-ignore
+/CONTRIBUTING.md export-ignore
 /dev-tools export-ignore
 /phpstan.neon export-ignore
 /phpunit.xml export-ignore
+/phpunit-windows.xml export-ignore
 /samples export-ignore
+/doc export-ignore
 /tests export-ignore
+/Makefile export-ignore
+/alt_autoload.php-dist export-ignore