Cache /usr/loca/lib

.travis.yml

@@ -29,8 +29,6 @@ jobs:
       - pytest --cov=freqtrade --cov-config=.coveragerc freqtrade/tests/
       - coveralls
       name: pytest
-      python:
-        - 3.7
     - script:
       - cp config.json.example config.json
       - python freqtrade/main.py --datadir freqtrade/tests/testdata backtesting
@@ -58,3 +56,4 @@ cache:
   pip: True
   directories:
     - ta-lib
+    - /usr/local/lib