Add llvm-toolchain-precise-4.0 another way
Add llvm-toolchain-precise-4.0 another way

It's not on the whitelist, so we have to be a bit more explicit. See
https://docs.travis-ci.com/user/installing-dependencies#Installing-Packages-with-the-APT-Addon

x4121/newsbeuter,der-lyse/newsboat,newsboat/newsboat,der-lyse/newsboat,x4121/newsbeuter,x4121/newsbeuter,newsboat/newsboat,newsboat/newsboat,x4121/newsbeuter,newsboat/newsboat,der-lyse/newsboat,der-lyse/newsboat,newsboat/newsboat,newsboat/newsboat,der-lyse/newsboat,der-lyse/newsboat,newsboat/newsboat,der-lyse/newsboat,newsboat/newsboat,der-lyse/newsboat