Update .travis.yml

Author: cclauss

.travis.yml

@@ -6,17 +6,18 @@ cache: pip
 before_install: pip install --upgrade pip setuptools six wheel --only-binary=numpy --only-binary=scipy
 jobs:
   include:
-    - script: pip install scipy
-    - script: pip install statsmodels
-    - script: pip install tensorflow
+    - install: true
+      script: pip install scipy
+    - install: true
+      script: pip install statsmodels
+    - install: true
+      script: pip install tensorflow
     - name: Build
       install: pip install pytest-cov -r requirements.txt
       script:
         - pytest --doctest-modules --ignore=project_euler/ --cov-report=term-missing:skip-covered --cov=. .
   allow_failures:
-    - script: pip install scipy
-    - script: pip install statsmodels
-    - script: pip install tensorflow    
+    - install: true   
 after_success:
   - scripts/build_directory_md.py 2>&1 | tee DIRECTORY.md
 notifications: