Add `packages: ['.']` to travis stack.yaml

.travis.yml

@@ -26,14 +26,14 @@ install:
   - stack --no-terminal install cabal-install --resolver=$RES
   - travis_retry cabal update
   - stack --no-terminal install happy --resolver=$RES
-  # - stack init --ignore-subdirs --resolver=ghc-$GHCVER ./ cabal-helper/
-  # - stack init --ignore-subdirs --resolver=ghc-$GHCVER ./
   - |
     resf="ghc-$GHCVER.yaml"
     echo "resolver: ghc-$GHCVER" > "$resf"
+    echo "packages: ['.']" >> "$resf"
     stack --no-terminal solver --update-config --stack-yaml="$resf"
     sed -i 's/^resolver:/compiler:/;s/^extra-deps:/packages:/' "$resf"
     echo "resolver: { name: 'ghc-$GHCVER', location: './$resf' }" > stack.yaml
+    echo "packages: ['.']" >> stack.yaml
     ir=$( stack path --snapshot-install-root )
     ls -d ${ir%/custom-ghc-*}/custom-ghc-* | grep -v "${ir%/*}" | while read i; do
       rm -rfv "$i"