fix comment error on tox and re-add cache for travis

.travis.yml

@@ -60,7 +60,9 @@ notifications:
     skip_join: true
     channels:
     - irc.freenode.org#scrapy
-
+cache:
+  directories:
+    - $HOME/.cache/pip
 deploy:
   provider: pypi
   distributions: "sdist bdist_wheel"

tox.ini

@@ -21,7 +21,8 @@ passenv =
     AWS_SECRET_ACCESS_KEY
     GCS_TEST_FILE_URI
     GCS_PROJECT_ID
-download = true #allow tox virtualenv to upgarde pip/wheel/setuptools
+#allow tox virtualenv to upgrade pip/wheel/setuptools
+download = true 
 commands =
     py.test --cov=scrapy --cov-report= {posargs:--durations=10 docs scrapy tests}
 install_command =