Travis CI build failing and .iml files pushed up

[albodelu]

Both kata-screenshot and master branches contain .iml files in their last commit.

This is problematic and we cannot create a pull request for a new branch to the upstream project.

Furthermore, the build-tools version was updated in Gradle but not in Travis CI.

For this reason, CI builds are failing because the license is not automatically accepted.

Please remove .iml files from GIT for good and update .travis.yml configuration like this.