Revert a change to try to fix travis on master. It is the only think I think…

.travis.yml

@@ -31,7 +31,7 @@ addons:
 
 install:
 # In Python 3.3, we test the min version of NumPy and SciPy. In Python 2.7, we test more recent version.
-  - if [[ $TRAVIS_PYTHON_VERSION == '2.7' ]]; then conda create --yes -q -n pyenv mkl python=2.7 numpy=1.11.1 scipy=0.18 nose=1.3.0 pip flake8=2.3 six=1.9.0 pep8=1.6.2 pyflakes=0.8.1 sphinx mkl-service; fi
+  - if [[ $TRAVIS_PYTHON_VERSION == '2.7' ]]; then conda create --yes -q -n pyenv mkl python=2.7 numpy=1.9.1 scipy=0.14.0 nose=1.3.0 pip flake8=2.3 six=1.9.0 pep8=1.6.2 pyflakes=0.8.1 sphinx mkl-service libgfortran=1; fi
   - if [[ $TRAVIS_PYTHON_VERSION == '3.3' ]]; then conda create --yes -q -n pyenv mkl python=3.3 numpy=1.9.1 scipy=0.14.0 nose=1.3.4 pip flake8=2.3 six=1.9.0 pep8=1.6.2 pyflakes=0.8.1 sphinx mkl-service; fi
   - source activate pyenv
   - if [[ $TRAVIS_PYTHON_VERSION == '2.7' ]]; then pip install pydot; else pip install pydot-ng; fi