Pass closure to stage steps
Pass closure to stage steps

After upgrading our Jenkins instance we were getting deprecation
messages in the pipeline builds:

    `Using the ‘stage’ step without a block argument is deprecated`

We now need to pass a closure to the stage step. Looks like there
is going to be a lot of rework around pipelines and step definitions,
so best to prepare for these changes now.

Carboni/the-train-destination,ONSdigital/The-Train,ONSdigital/The-Train,Carboni/the-train-destination,Carboni/The-Train,Carboni/The-Train