automatically commit a file every n seconds

I wrote this in order to automatically post a script as it's being develop, in a live-coding workshop.

Run like:

autocommit.rb [filename] [n]

where filename is the file to repeatedly commit and push and n is the number of seconds to delay between attempts. If n is missing, we use 10 sec; if n<2 we use 2.

You need to be in the git repository that contains the file, and you need to have already set up a remote.