Merge branch 'patch-meta_in_summary' into 'develop'

Patch meta in summary

This pull request adds a `meta` entry to the root of each summary JSON file. The contents of the meta is:

`last_commit_hash`: the commit hash of the repository when the JAR was built. If the repository has uncommitted changes, `-dirty` is appended to the commit hash.

`pipeline_version`: the version of the pipeline (the one we put in the `pom.xml` file).

This information is static across all modules and subpipelines to any given pipeline run, so I decided to put this in the root.

See merge request !144