Update .travis.yml

.travis.yml

@@ -68,8 +68,8 @@ before_install:
     python -V;
   fi
 - curl https://bootstrap.pypa.io/get-pip.py | sudo python
-- pip freeze > requirements.txt && pip install --upgrade -r requirements.txt && rm requirements.txt
-- pip install pyinstaller
+- sudo pip freeze > requirements.txt && sudo pip install --upgrade -r requirements.txt && sudo rm requirements.txt
+- sudo pip install pyinstaller
 
 install:
 - cd src