exclude some files from archive (#95)

Co-authored-by: Samuel Weirich <samuel.weirich@gmx.de>

Author: sualko

.gitattributes

@@ -0,0 +1,8 @@
+.gitattributes export-ignore
+.gitignore export-ignore
+/.github export-ignore
+codeception.yml export-ignore
+.php_cs export-ignore
+phpunit.xml.dist export-ignore
+psalm.xml export-ignore
+/tests export-ignore