Merge pull request #12447 from codingCoffee/travis-fix

mongodb removed from travis
diff --git a/.travis.yml b/.travis.yml
index 43b4078..03e75b6 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -15,6 +15,8 @@
   - mysql
 
 install:
+  # fix mongodb travis error
+  - sudo rm /etc/apt/sources.list.d/mongodb*.list
   - pip install flake8==3.3.0
   - flake8 . --count --select=E901,E999,F821,F822,F823 --show-source --statistics
   - sudo rm /etc/apt/sources.list.d/docker.list