JavaScript pipelines (for coverage, commitlint and codelint) to run nodejs 8.11.3

[victorb]

From https://github.com/ipfs-shipyard/ipfs-webui/pull/728#issuecomment-406271586

[victorb]

Should be simple, involves changing the version in three places

• https://github.com/ipfs/jenkins-libs/blob/master/vars/javascript.groovy#L149
• https://github.com/ipfs/jenkins-libs/blob/master/vars/javascript.groovy#L170
• https://github.com/ipfs/jenkins-libs/blob/master/vars/javascript.groovy#L191

[victorb]

It does since a while ago!