message: ci: disable target and registry cache
  Target cache seems not work for a long time.
  Registry cache is network boundary. It cannot save time to download from
  travis instead of crates registry.
diff: @@ -8,7 +8,6 @@ cache:
  timeout: 1024
  directories:
  - $HOME/.cargo
  - - target-cache
  env:
  global:
  @@ -38,8 +37,5 @@ script:
  - make info
  - make "$SUITE"
  -before_install:
  -- make cache-warm
  -
  before_cache:
  -- make cache-clean
  +- rm -rf $HOME/.cargo/registry
  