[minor-refactor] Add trailing newline to all text files.

Present in the large majority of files of each respective type.

The only filetype for which we could be not sure is the `.txt` because there is only one other, but let's follow the other files and do it.

Bit me when doing `perl -lapi -e`, needed to change to `perl -pi -e`, or else newlines were added.

Refactoring command used:

    git grep -Ile '' | grep -Ev '^vendor' | xargs perl -lapi -e 's/.*/$&/'

`-Ile ''` to ignore binary files: http://stackoverflow.com/questions/18973057/list-all-text-non-binary-files-in-repo