Ignore the Mac DS Store files

This is usually added to a more 'global' config file, usually called
.gitignore in your home folder.  Because it is more system related that
project related.  However, for learning purposes, I have added it here
for posterity.
As to not bother other systems
Merge branch 'master' of github.com:hpjaj/myrubyprograms

* 'master' of github.com:hpjaj/myrubyprograms:
  As to not bother other systems