Jeversmann/kochiku yml updates

Changes build enqueueing logic so that test command, on success script, and log file targets from kochiku.yml. I also moved the logic for interacting with the GitRepos around to eliminate cases where methods were making assumptions about how they were being called.
I still think we should use a git command to view the contents of kochiku.yml to save us from having to do the inside copy.
```
git show ref:path/to/kochiku.yml
```
It is unfortunate that we support three different locations so we will have to run git show on each location until we find it but that will still be faster than an `inside_copy`.