Revert ":octocat: Added .gitattributes & .gitignore files"

This reverts commit 9da1528bfe8ae95879150abce23ce39bf7349f06.
Revert "Revert ":octocat: Added .gitattributes & .gitignore files""

This reverts commit 7c820d722cba59b2a4b48da98a2631e2dca380b5.
cachematrix.R