Update .travis.yml with new exec cmd for docker

will now run `/bin/bash -c 'cd /code; /code/tests/run_tests.sh'`

Former-commit-id: 43bb335

.travis.yml

@@ -16,7 +16,7 @@ before_script:
 script:
 - pwd
 - ls
-- docker run -e TRAVIS_JOB_ID="$TRAVIS_JOB_ID" -e TRAVIS_BRANCH="$TRAVIS_BRANCH" -e DIST=${DIST} -e CODECOV_TOKEN=${CODECOV_TOKEN} -it ${DIST}:latest "cd /code; /code/tests/run_tests.sh"
+- docker run -e TRAVIS_JOB_ID="$TRAVIS_JOB_ID" -e TRAVIS_BRANCH="$TRAVIS_BRANCH" -e DIST=${DIST} -e CODECOV_TOKEN=${CODECOV_TOKEN} -it ${DIST}:latest /bin/bash -c 'cd /code; /code/tests/run_tests.sh'
 
 after_success:
   - docker login -u $DOCKER_USER -p $DOCKER_PASS