Travis: Fix CA problem for Trusty

Author: iakov

.travis.yml

@@ -95,6 +95,7 @@ matrix:
       - sudo add-apt-repository -y ppa:deadsnakes/ppa
       - sudo apt update
       - sudo apt-get install -y --no-install-recommends python3.7
+      - curl -vLo /etc/ssl/certs/cacert.pem https://curl.haxx.se/ca/cacert.pem && sudo update-ca-certificates
       script:
       - ./buildScripts/travis/run_clean_env_test.sh
     - os: osx