install pylearn2 automatically

[AlbertDeFusco]

this fixes the issue brought up in PR #541

[ilanschnell]

I tried your change, but it doesn't work for me. I get:

+ echo install
+ /home/ilan/minonda/envs/_build/bin/python setup.py install
/home/ilan/anaconda/packages/pylearn2/build.sh: line 3:  1377 Done                    echo "install"
      1378 Illegal instruction     | $PYTHON setup.py install

[jakirkham]

If you would be interested in adding this to conda-forge, @AlbertDeFusco, we would be more than happy to help you. Just follow the instruction in the README to get started. Please ask if you have any questions.