[fix] travis: workspace settings (#3125)
[fix] travis: workspace settings (#3125)

* [WIP] travis: $TRAVIS_BUILD_ID

* [fix] travis: use $TRAVIS_BUILD_NUMBER

shirasagi/shirasagi,sunny4381/shirasagi,ShinjiTanimoto/shirasagi,ShinjiTanimoto/shirasagi,tany/ss,shirasagi/shirasagi,tany/ss,tany/ss,sunny4381/shirasagi,shirasagi/shirasagi,shirasagi/shirasagi,ShinjiTanimoto/shirasagi,sunny4381/shirasagi,sunny4381/shirasagi,tany/ss,ShinjiTanimoto/shirasagi