Automatically update pipeline steps when versionstream is updated

[tomhobson]

Pipeline files should receive automatic updates when a newer version of jx is released.

It's important for us to keep to the same major version.
Unsure about minor but would certainly work for patch.

Ie 2.1.7 -> 2.1.8
3.0.1 -> 3.0.3

This will save a lot of headaches when updating microservices pipelines.

[jenkins-x-bot]

Issues go stale after 90d of inactivity.
Mark the issue as fresh with /remove-lifecycle stale.
Stale issues rot after an additional 30d of inactivity and eventually close.
If this issue is safe to close now please do so with /close.
Provide feedback via https://jenkins-x.io/community.
/lifecycle stale