Link Modeller Python libs into virtualenv location.

.travis.yml

@@ -3,15 +3,14 @@ python:
   - 2.6
   - 2.7
   - 3.5
-virtualenv:
-  # Need to be able to find Modeller in system Python directories
-  system_site_packages: true
 install:
   - wget $LICENSE_URL -O mod-license
   - sudo apt-get -qq update
   - sudo apt-get install -y libhdf5-serial-dev swig
   - wget http://salilab.org/modeller/9.17/modeller_9.17-1_amd64.deb
   - KEY_MODELLER=`cat mod-license` sudo dpkg -i modeller_9.17-1_amd64.deb
+  - ln -sf /usr/lib/python$TRAVIS_PYTHON_VERSION/dist-packages/_modeller.so $HOME/virtualenv/*/lib/*/site-packages/
+  - ln -sf /usr/lib/python$TRAVIS_PYTHON_VERSION/dist-packages/modeller $HOME/virtualenv/*/lib/*/site-packages/
 script:
   - mkdir build
   - cd build