Travis CI: pip install scipy

.travis.yml

@@ -14,7 +14,7 @@ matrix:
         - python: pypy3
 install:
     #- pip install -r requirements.txt
-    - pip install flake8 tensorflow  # pytest  # add another testing frameworks later
+    - pip install flake8 scipy tensorflow  # pytest  # add another testing frameworks later
 before_script:
     # stop the build if there are Python syntax errors or undefined names
     - flake8 . --count --select=E901,E999,F821,F822,F823 --show-source --statistics