fixup! symlink [skip appveyor]

Author: blueyed

.travis.yml

@@ -33,7 +33,7 @@ jobs:
       before_install:
         - which python3
         - python3 --version
-        - ln -s "$(which python3)" /usr/local/bin/python
+        - ln -sfn "$(which python3)" /usr/local/bin/python
         - python -V
         - test $(python -c 'import sys; print("%d%d" % sys.version_info[0:2])') = 37