Find a way to update the default image version of tyk components

[letzya]

As a user I want tyk-demo to have the latest working image of the tyk-components.

tyk-demo has default versions in the docker-compose.yaml files to make it easier for users to get up and running. The problem is to remember to update the versions in these files. We cant do it straight after the release since we sometimes have bugs). Should find a way to do that.

Context:
During PR review, we realised that the pump is crashing. Once we updated it to 1.4.0 (from 1.1) everything worked as expected. It took us time to realised that and the version of the pump is not something that pops out.

Possible solution:
We can add an interactive check to the bootstrap, in which, we look for a new version and suggest the user to update his .env and also create PR to update the docker-compose.yaml files? This will also ran as part of the GH actions so we can be notified. (needless to say it needs to have ignore/skip flag to make sure it's not interactive and in case we dont want to upgrade).