Use mkdir_p so app can start if log dir already exists

The way it was, if the log dir existed but localeapp.yml did not, the app would blow up:

```
Errno::EEXIST: File exists - /home/deploy/buildAgent/work/8823f7f94dd0e3f9/log
```
Merge pull request #112 from aaronjensen/patch-1

Use mkdir_p so app can start if log dir already exists