Bugfix reg check

Closes issues #216 and #302, plus addresses a separate issue where vagrant wouldn't work using a samba share.
This should probably be an integer, e.g.

```
year = integer(default=0)
```

The main reason to keep it a string is if you plan on having wacky years, like maybe year 2 of MAGFest 8.5 will be '3/4' or something.