Another stab at Travis

Author: snoyberg

.travis.yml

@@ -87,6 +87,7 @@ install:
        echo "stack is located at $(which stack)";
        stack --version;
        rm -f $(stack --stack-yaml=$STACK_YAML path --dist-dir)/stack-*.tar.gz &&
+       stack --system-ghc --stack-yaml=$STACK_YAML build Cabal &&
        stack --system-ghc --stack-yaml=$STACK_YAML sdist --pvp-bounds=both &&
        tar xf $(stack --system-ghc --compiler=ghc-$GHCVER path --dist-dir)/stack-*.tar.gz --wildcards --strip-components=1 '*/stack.cabal' &&
        cabal install --only-dependencies --enable-tests --enable-benchmarks --force-reinstalls --ghc-options=-O0 --reorder-goals --max-backjumps=-1;;