Update .gitattributes

File was out of date, some files were missing or renamed.

Author: Willem Stuursma-Ruwen

.gitattributes

@@ -1,7 +1,11 @@
-/Tests           export-ignore
-/.gitattributes  export-ignore
-/.gitignore      export-ignore
-/.php_cs         export-ignore
-/.travis.yml     export-ignore
-/README.markdown export-ignore
-/Upgrade.md      export-ignore
+/.github         export-ignore
+/.gitattributes   export-ignore
+/.gitignore       export-ignore
+/.php_cs.dist	    export-ignore
+/.travis.yml      export-ignore
+/Changelog.md     export-ignore
+/Makefile         export-ignore
+/README.md        export-ignore
+/Tests            export-ignore
+/Upgrade.md       export-ignore
+/phpunit.xml.dist export-ignore