ci: resolve warnings

.travis.yml

@@ -1,7 +1,8 @@
 version: ~> 1.0
 import: nix-community/nix-travis-ci:nix.yml@main
 
-sudo: false
+dist: xenial
+os: linux
 
 env:
   global:
@@ -16,13 +17,13 @@ jobs:
     - env: NIX_PATH=nixpkgs=channel:nixos-20.03
 
 script:
- - nix-build ci.nix -A buildOutputs
+ - nix-build ci.nix -kA buildOutputs
  - nix eval -f default.nix 'lib'
  - nix eval -f default.nix 'modules'
  - nix eval -f default.nix 'overlays'
 
 after_success:
-  - if [ -n "${CACHIX_CACHE}" ]; then nix-build ci.nix -A cacheOutputs | cachix push "${CACHIX_CACHE}"; fi
+  - if [ -n "${CACHIX_CACHE}" ]; then nix-build ci.nix -kA cacheOutputs | cachix push "${CACHIX_CACHE}"; fi
   - if [[ "cron" != "${TRAVIS_EVENT_TYPE}" && "false" = "${TRAVIS_PULL_REQUEST}" && "master" = "${TRAVIS_BRANCH}" ]]; then
       curl -XPOST "https://nur-update.herokuapp.com/update?repo=${NUR_REPO}"; fi