Add retest slash command to CI

Author: stefanprodan

.github/workflows/rebase.yaml

@@ -8,7 +8,7 @@ on:
 
 jobs:
   rebase:
-    if: github.event.issue.pull_request != '' && contains(github.event.comment.body, '/rebase') && github.event.comment.author_association == 'CONTRIBUTOR'
+    if: github.event.issue.pull_request != '' && contains(github.event.comment.body, '/rebase') && (github.event.comment.author_association == 'CONTRIBUTOR' || github.event.comment.author_association == 'MEMBER')
     runs-on: ubuntu-latest
     steps:
       - name: Checkout the latest code

.github/workflows/test.yaml

@@ -5,9 +5,12 @@ on:
   push:
     branches:
       - master
+  issue_comment:
+    types: [created]
 
 jobs:
   unit:
+    if: github.event_name == 'push' || github.event_name == 'pull_request' || contains(github.event.comment.body, '/retest')
     runs-on: ubuntu-latest
     steps:
       - name: Checkout