message: Update travis.yml according to travis backend errors and warns
  Namely:
  root: deprecated key sudo (The key `sudo` has no effect anymore.)
  language: value minimal is an alias for shell, using shell
  root: key matrix is an alias for jobs, using jobs
diff: -sudo: required
  dist: xenial
  os: linux
  -language: minimal
  +language: shell
  cache:
  ccache: true
  directories:
  @@ -31,7 +30,7 @@ env:
  - DIST=DEB
  - CACHE_ERR_MSG="Error! Initial build successful, but not enough time remains to run later build stages and tests. Please manually re-run this job by using the travis restart button or asking a bitcoin maintainer to restart. The next run should not time out because the build cache has been saved."
  -matrix:
  +jobs:
  include:
  #x86_64 Linux + deps as via system lib
  - compiler: gcc
  