Task/add unit tests

#### Reviewers
@jframos @flopezag @jesuspg 

#### Description
ADD unit tests

#### Test
tested locally 
I mean, why do you not only make it:

productInstance = productInstanceManager.install(tierInstance, claudiaData, envInstance,
                        productRelease);

And internally:

xxx install(aaa tierInstance, bbb claudiaData, ccc envInstance, ddd productRelease)
{
  Attributes attr = productRelease.getAttributes();
}