Use prebuilt stackage-curator executable

.travis.yml

@@ -1,11 +1,6 @@
 env:
  - CABALVER=1.20 GHCVER=7.8.4
 
-cache:
- directories:
- - $HOME/.ghc
- - $HOME/.cabal
-
 # Note: the distinction between `before_install` and `install` is not important.
 before_install:
  - travis_retry sudo add-apt-repository -y ppa:hvr/ghc
@@ -17,8 +12,10 @@ install:
  - cabal --version
  - echo "$(ghc --version) [$(ghc --print-project-git-commit-id 2> /dev/null || echo '?')]"
  - travis_retry cabal update
- - cabal install -j
+ - wget https://s3.amazonaws.com/stackage-travis/stackage-curator.bz2
+ - bunzip2 stackage-curator.bz2
+ - chmod +x stackage-curator
 
 # Here starts the actual work to be performed for the package under test; any command which exits with a non-zero exit code causes the build to fail.
 script:
- - ./dist/build/stackage/stackage check
+ - ./stackage-curator check