Revert "build scratch-vm."

This reverts commit ae22ff1.

Author: takaokouji

.travis.yml

@@ -19,9 +19,11 @@ 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 run build)
 script:
+- npm run test:lint
 - npm run test:unit
+- npm run clean && npm run setup-opal && $(npm bin)/webpack --colors --bail --silent
+- npm run test:integration
 deploy:
 - provider: script
   on: