Fix path to build directory

.travis.yml

@@ -21,5 +21,5 @@ after_script:
     # Publish to gh-pages as most recent committer
     git config --global user.email $(git log --pretty=format:"%ce" -n1)
     git config --global user.name $(git log --pretty=format:"%cn" -n1)
-    ./node_modules/.bin/gh-pages -x -r https://${GH_TOKEN}@github.com/${TRAVIS_REPO_SLUG}.git -d playground -m "Build for $(git log --pretty=format:%H)"
+    ./node_modules/.bin/gh-pages -x -r https://${GH_TOKEN}@github.com/${TRAVIS_REPO_SLUG}.git -d build -m "Build for $(git log --pretty=format:%H)"
   fi