Add debug statement about downloading miniconda.
Add debug statement about downloading miniconda.

ronert/python-conda-buildpack,ihuston/python-conda-buildpack,pl31/ipython-notebook-buildpack,p-a-c-o/ipython-notebook-buildpack,pl31/heroku-buildpack-conda,gmarkall/python-conda-buildpack,yepengxj/conda-buildpack-test