Help update Dockerfile to adjust docker build with ruby-25-rhel7 image

[xiuwang]

Hi, anyone could help update Dockerfile to adjust docker build with ruby-25-rhel7?
Since from 4.2, the openshift/ruby:2.2 imagestreamtag is end of life in openshift cluster.
Thanks~

[wewang58]

@adambkaplan @gabemontero @coreydaley anyone takes time to update this to be compatible with ruby 2.5, now our qe ci automation failed of this, though I saw it's in todo e2e list: https://github.com/openshift/origin/blob/master/test/extended/builds/start.go#L284, thanks very much.

[adambkaplan]

@wewang58 you can probably give this a shot yourselves, we'd be happy to review a PR.

What you'll need to do is as follows:

1. Switch the Dockerfile to use the ruby-25-centos7 image
2. On a machine or container with ruby 2.5, update the Gemfile to use compatible versions of the gems. Run bundle install and commit the resulting Gemfile and Gemfile.lock files.
3. Submit a PR with the results.

[pvalena]

Implemented in #85 AFAICT.

[openshift-bot]

Issues go stale after 90d of inactivity.

Mark the issue as fresh by commenting /remove-lifecycle stale.
Stale issues rot after an additional 30d of inactivity and eventually close.
Exclude this issue from closing by commenting /lifecycle frozen.

If this issue is safe to close now please do so with /close.

/lifecycle stale

[openshift-bot]

Stale issues rot after 30d of inactivity.

Mark the issue as fresh by commenting /remove-lifecycle rotten.
Rotten issues close after an additional 30d of inactivity.
Exclude this issue from closing by commenting /lifecycle frozen.

If this issue is safe to close now please do so with /close.

/lifecycle rotten
/remove-lifecycle stale

[openshift-bot]

Rotten issues close after 30d of inactivity.

Reopen the issue by commenting /reopen.
Mark the issue as fresh by commenting /remove-lifecycle rotten.
Exclude this issue from closing again by commenting /lifecycle frozen.

/close

[openshift-ci-robot]

@openshift-bot: Closing this issue.

In response to this:

Rotten issues close after 30d of inactivity.

Reopen the issue by commenting /reopen.
Mark the issue as fresh by commenting /remove-lifecycle rotten.
Exclude this issue from closing again by commenting /lifecycle frozen.

/close

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.