Add second `exclude` value in readme example

In #87 it became apparent that our documentation is not clear enough in
regards to how to exclude multiple things. This commit attempts to
clarify that some by adding to the example in the readme.

Change-Id: Ia6706dfbb0106ebcebfff99f393e16b89c26fa1d
Reviewed-on: http://gerrit.causes.com/36074
Tested-by: jenkins <jenkins@causes.com>
Reviewed-by: Shane da Silva <shane@causes.com>