ci: add fixup check to Github Actions

.github/workflows/fixup_check.yml

@@ -0,0 +1,11 @@
+name: Git Checks
+
+on: [pull_request]
+
+jobs:
+  block-fixup:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2.0.0
+      - name: Block Fixup Commit Merge
+        uses: 13rac1/block-fixup-merge-action@v2.0.0

ci/check_fixup.sh

@@ -1,12 +0,0 @@
-#!/usr/bin/env bash
-
-git fetch origin master:master  # on CIs it is common to fetch only the current branch
-
-messages=$(git log --format=%s master..)  # commit messages between this branch and master
-
-if [[ $messages =~ "fixup!" ]]; then
-  echo 'Failure: Some commit message contains "fixup!" string.'
-  exit 1
-else
-  echo 'Success: No commit messages containing "fixup!" string.'
-fi