Rename finalDestination 

To make it clearly overloadable.
Change meaning of destination for test files

minit templates should now easily mirror the directory structure of the 
project.
For example a component created with

```
minit create:component -n name -d ui/subdir
minit create:test -n name -d ui/subdir
```

will create

```
ui/subdir/name.reel/...
test/ui/subdir/name/name-spec.js
test/ui/subdir/name/...
```

Fixes gh-25