Issue/419

This branch allows adds an extra step to the install routine to clone the 'adapt_framework' repository from GitHub.  (Note that in future this could possibly move to a bower package instead)

For each tenant, a copy is made of this repository, and is used to dynamically compile the course, e.g. so that different themes can be used.  In future this could also be used to deliver customised installs.
should be:
````
return callback(error);
````

otherwise, the rest of the function will continue, and you'll get multiple callbacks + undefined behaviour