Merge branch 'release/4.7.0' into develop
Added tags to metadata.json.
Fix issues_url in metadata.json.
Drop support of OSs not supported by VMware.

Specifically do not allow installation on RHEL 7. Solves GH25.
Update README.md with OS support limits.
Merge branch 'feature/el7' into develop
Update versions for 4.8.0 release.
Merge branch 'release/4.8.0'