ci: add mini-e2e Jenkins job

The new mini-e2e jobs does the following:
 - reserve a bare-metal machine
 - checkout the git repository with the PR
 - build used artifacts (container image and e2e.test executable)
 - deploy k8s and Rook in a minikube VM
 - run the e2e tests

With-contributions-from: Yug <yuggupta27@gmail.com>
Signed-off-by: Niels de Vos <ndevos@redhat.com>

jobs/mini-e2e.yaml

@@ -0,0 +1,35 @@
+---
+- job:
+    name: mini-e2e
+    project-type: pipeline
+    sandbox: true
+    concurrent: true
+    properties:
+      - github:
+          url: https://github.com/ceph/ceph-csi
+      - build-discarder:
+          days-to-keep: 7
+          artifact-days-to-keep: 7
+    pipeline-scm:
+      scm:
+        - git:
+            name: origin
+            url: https://github.com/ceph/ceph-csi
+            branches:
+              - ci/centos
+      script-path: mini-e2e.groovy
+      lightweight-checkout: true
+    triggers:
+      - github-pull-request:
+          status-context: ci/centos/mini-e2e
+          trigger-phrase: '/(re)?test ((all)|(ci/centos/mini-e2e))'
+          permit-all: true
+          # TODO: set github-hooks to true when it is configured in GitHub
+          github-hooks: false
+          cron: 'H/5 * * * *'
+          black-list-target-branches:
+            - ci/centos
+          admin-list:
+            - nixpanic
+          org-list:
+            - ceph