Consider updating meteor launchpad version in Dockerfile

[phanimahesh]

Is there a reason why we're still using meteor-launchpad v1.1.1 which is more than a year old when the latest is v2.3.0? If yes, document it in the dockerfile. If not, then update.

Last commit was on Nov 22 2016 by @shaliko

[Nazarah]

@phanimahesh have you come up with any plan about this? Please have a discussion with @ilarimikkonen about it.