fix: conda install

Author: satra

.travis.yml

@@ -24,7 +24,9 @@ before_install:
 
 # Install packages
 install:
-  - conda install --yes pip python=$TRAVIS_PYTHON_VERSION numpy scipy nose traits networkx dateutil
+  - conda create -n testenv --yes pip python=$TRAVIS_PYTHON_VERSION
+  - source activate testenv
+  - conda install numpy scipy nose traits networkx dateutil
   - pip install nibabel --use-mirrors
   - pip install python-coveralls --use-mirrors
   - pip install nose-cov --use-mirrors