Bug in syntax for new numpy version (cont'd)

Author: rtavenar

.travis.yml

@@ -28,7 +28,7 @@ install:
   - pip install -r requirements.txt
   - pip install "numpy>=1.14" "scipy<1.3"  # for numpy array formatting in doctests
   # ^ scipy version: otherwise, pymanopt fails, cf <https://github.com/pymanopt/pymanopt/issues/77>
-  - python -c "import numpy; import scipy; print('numpy: ', numpy.__version__); print('scipy: ', scipy.__version__)"
+  - python -c "import numpy; import scipy; print(\"numpy: \", numpy.__version__); print(\"scipy: \", scipy.__version__)"
   - pip install flake8 pytest "pytest-cov<2.6"
   - pip install .
 # command to run tests + check syntax style