build scratch-vm on TravisCI.

Author: takaokouji

.travis.yml

@@ -19,6 +19,7 @@ before_install:
 - '[[ $(node -v) =~ ^v9.*$ ]] || npm install -g npm@latest' # skipped when using node 9
 install:
 - npm --production=false install
+- (cd node_modules/scratch-vm && npm --production=false install && $(npm bin)/webpack --colors --bail --silent)
 script:
 - npm run test:lint
 - npm run test:unit