Deleting a folder from svn repository
Solution 1:
Looks like a commit message is required, and you do not have your system configured to launch an editor for you to add one (without specifying on the command line).
Try this:
svn delete http://www.yourrepository.com/svn/folder --message "Deleting"
Solution 2:
To avoid similar messages in the future, add something like export SVN_EDITOR="/usr/bin/vim"
to your .bash_profile (or something similar for your Mac :))
Solution 3:
You can use 2 step delete and commit for this as well. No need to use repository URL.
svn delete filename1 filename2 forldername1
svn commit -m "[Message] Unwanted files and folder."