Differentiate file from folder in session

[fernandoeqc]

It would be interesting to use the session '-s' command to differentiate a file from a folder, placing a '/' at the end of the folder. This is especially helpful when working with files without an extension. If the change is welcome, I would be happy to do a PR

~/rip$ rip folder/
~/rip$ rip file
~/rip$ rip -s
/tmp/user/rip/folder/
/tmp/user/rip/file