revert format_script.sh change

Now that we correctly fetch the base_ref, we can put the format_script back into Travis-compatible state.

Author: egpbos

.ci/format_script.sh

@@ -2,7 +2,7 @@
 
 set -ex
 
-# BASE_COMMIT=$(git rev-parse $TRAVIS_BRANCH)
+BASE_COMMIT=$(git rev-parse $TRAVIS_BRANCH)
 echo "Running clang-format against branch $TRAVIS_BRANCH, with hash $BASE_COMMIT"
 COMMIT_FILES=$(git diff --name-only $BASE_COMMIT | grep -i -v LinkDef)
 RESULT_OUTPUT="$(git-clang-format --commit $BASE_COMMIT --diff --binary `which clang-format` $COMMIT_FILES)"

.github/workflows/code_analysis.yml

@@ -12,7 +12,7 @@ jobs:
     env:
       TRAVIS_BRANCH: ${{ github.base_ref }} 
       TRAVIS_PULL_REQUEST_BRANCH: ${{ github.head_ref }}
-      BASE_COMMIT: ${{ github.event.pull_request.base.sha }}
+      # BASE_COMMIT: ${{ github.event.pull_request.base.sha }}
     steps:
     - uses: actions/checkout@v2
     - name: Fetch base_ref HEAD