Revert "Added DS_Store to .gitignore"

This reverts commit fe0115cad59f84d859fcbe225e41a5f63027f701.
Revert "Revert "Added DS_Store to .gitignore""

This reverts commit 5ee00cd19e0b4ca55a07a8d28afe3ea1024c9fd0.
Remove DS_Store