Add Gitlab::VersionInfo class to fix and simplify version check.
It returns "yes" if required version is "1.7.10" and current version is "1.6.10", because the patch version of current version equals to that of required version.
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
It returns "yes" if required version is "1.7.10" and current version is "1.6.10", because the patch version of current version equals to that of required version.