fix(.travis.yml): remove evm, fix apt sources
fix(.travis.yml): remove evm, fix apt sources

Read https://github.com/travis-ci/apt-source-whitelist#source-approval-process

leanprover/tutorial,cjmazey/fork_leanprover_tutorial,fpvandoorn/tutorial,cjmazey/fork_leanprover_tutorial,leanprover/tutorial,avigad/tutorial,cjmazey/fork_leanprover_tutorial,fpvandoorn/tutorial,avigad/tutorial,fpvandoorn/tutorial,soonhokong/lean-tutorial,Hodapp87/cs6460_project,avigad/tutorial,soonhokong/lean-tutorial,soonhokong/lean-tutorial,Hodapp87/cs6460_project,Hodapp87/cs6460_project,leanprover/tutorial