RF: switch travis tests to use virtualenvs

We were using a trick to get the dependencies on travis, working round their
virtualenv setup.

Now there is a usable travis wheel repository, we can use our own virtualenvs
and install all optional dependencies.

Also allows checking minimal dependencies, and Pythons 2.6 through 3.4.
Thanks for the tip: https://github.com/nipy/dipy/pull/478

On Sun, Nov 23, 2014 at 9:59 AM, Olivier Grisel <notifications@github.com>
wrote:

> In .travis.yml:
>
> > +    - 3.4
> > +matrix:
> > +  include:
> > +    - python: 2.7
> > +      env:
> > +        - COVERAGE=1
> > +    # To test minimum dependencies
> > +    - python: 2.7
> > +      env:
> > +        - DEPENDS="cython==0.18 numpy==1.6.0 scipy==0.9.0 nibabel"
> > +before_install:
> > +    - virtualenv venv
> > +    - source venv/bin/activate
> > +    - pip install nose # always
> > +    - sudo apt-get install libblas-dev liblapack-dev libatlas3gf-base
> > +    - pip install --no-index -f http://travis-wheels.scikit-image.org $DEPENDS
>
> FYI It might help to increase the timeout if the network is not very
> reliable:
>
> pip install --timeout=60 ...
>
> otherwise some noticed unstable build with the default timeout of 15
> seconds.
>
> —
> Reply to this email directly or view it on GitHub
> <https://github.com/nipy/dipy/pull/474/files#r20766386>.
>