Merge branch 'master' into prerelease_add

.github/workflows/version_change_check.yml

@@ -11,10 +11,11 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@v2
-
+        with:
+          fetch-depth: 2
       - name: Check if file is modified
         run: |
-          if git diff --unified=0 ${{ github.base_ref }}..${{ github.sha }} -- *conanfile.py* | grep -q "^+.*version"; then
+          if git diff -r HEAD^1 HEAD -- conanfile.py | egrep "[ ]+version = "; then
             echo "Version is updated with this PR, OK"
           else
             echo "Conan version is not updated with this PR. Please update that to allow PR merge"