code review

Hi Tom. I've set up a "pull request" [1] for your code, which we can use to communicate about it. I did this by forking your repo [2] and then:
```bash
# clone my fork onto my machine
$ git clone https://github.com/instinfctive/P-and-S.git
# create an empty branch that contained only your first (no files) commit
# (note that 'empty' is an arbitrary name - could have named it potato and
# this would still work)
$ git branch empty fa16937a0b66e03f41d283787aa6977436ccd865
# push that branch to github
$ git push origin empty
```
Then I set up the pull request [1] to compare the master and 'empty' [3].

Now we can talk about your code!

[1] https://help.github.com/articles/using-pull-requests
[2] https://help.github.com/articles/fork-a-repo
[3] http://astrofrog.github.io/blog/2013/04/10/how-to-conduct-a-full-code-review-on-github/