fix(composer) Exclude more demo files from composer downloads

Author: klausi

.gitattributes

@@ -1,4 +1,9 @@
-/.gitattributes export-ignore
 /.coveralls.yml export-ignore
+/.gitattributes export-ignore
+/.gitignore export-ignore
 /.travis.yml export-ignore
+/demo-old export-ignore
+/demo1 export-ignore
+/demo2 export-ignore
+/phpdoc.xml export-ignore
 /tests export-ignore