Add scipy 1.4-dev to travis

.travis.yml

@@ -13,6 +13,11 @@ python:
   - 3.5
   - 3.6
 
+matrix:
+  include:
+    - python: 3.7
+      env: SCIPY_WHEELS="https://7933911d6844c6c53a7d-47bd50c35cd79bd838daf386af554a83.ssl.cf2.rackcdn.com/"
+
 branches:
     except:
         - gh-pages
@@ -32,9 +37,16 @@ before_install:
   - conda info -a
 
 install:
-  - conda create -q -n test-environment python=$TRAVIS_PYTHON_VERSION nomkl numpy scipy cython setuptools
+  - conda create -q -n test-environment python=$TRAVIS_PYTHON_VERSION nomkl numpy cython setuptools
   - conda install -q -n test-environment dask=0.15.0 || true
-  - source activate test-environment
+  - |
+    if [ -z "$SCIPY_WHEELS" ]; then
+      conda install -q -n test-environment scipy
+      source activate test-environment
+    else
+      source activate test-environment
+      pip install --pre --upgrade --timeout=60 -f "$SCIPY_WHEELS" scipy
+    fi
   - python setup.py -v build_ext --inplace
 
 script: