fix(composer): Exclude test files from Composer production downloads

Author: pitbulk

.gitattributes

@@ -0,0 +1,12 @@
+/.coveralls.yml export-ignore
+/.gitattributes export-ignore
+/.gitignore export-ignore
+/.travis.yml export-ignore
+/demo-old export-ignore
+/demo1 export-ignore
+/demo2 export-ignore
+/endpoints export-ignore
+/locale export-ignore
+/tests export-ignore
+/_toolkit_loader.php
+/phpdoc.xml export-ignore