Travis-ci build failed because it automatically routed the builds to Ubuntu Trusty, which is the Ubuntu distribution used by default now. However, the builds is supposed to work in Ubuntu Precise which has reached the end of life.
check following
https://blog.travis-ci.com/2017-07-11-trusty-as-default-linux-is-coming
related Issue
#6624
Travis-ci build failed because it automatically routed the builds to Ubuntu Trusty, which is the Ubuntu distribution used by default now. However, the builds is supposed to work in Ubuntu Precise which has reached the end of life.
check following
https://blog.travis-ci.com/2017-07-11-trusty-as-default-linux-is-coming
related Issue
#6624