fix: build before example run

Author: achingbrain

.travis.yml

@@ -134,6 +134,7 @@ jobs:
         - npx json -I -f ./lerna.json -e "this.packages.push('examples/*')"
         - npm run reset
         - npm install
+        - npm run build -- $RUN_SINCE --scope={ipfs,ipfs-http-client}
         - npm run test -- --scope=example* --concurrency=1
 
     - stage: release-rc-npm