chore: checkout corresponding branch instead of commit (#477)

* chore: checkout corresponding branch instead of commit

* fetch only what we want

* remove ;

* use commit id instead of branch

* fetch commit id instead of branch

Author: josecorella

Diff for: codebuild/release/prod-release.yml

@@ -1,8 +1,6 @@
 version: 0.2
 
 env:
-  variables:
-    BRANCH: "master"
   secrets-manager:
     TWINE_USERNAME: PyPiAdmin:username 
     TWINE_PASSWORD: PyPiAdmin:password
@@ -14,7 +12,8 @@ phases:
   build:
     commands:
       - pip install tox
-      - git checkout $BRANCH
+      - git fetch origin $COMMIT_ID:$COMMIT_ID --depth=1
+      - git checkout $COMMIT_ID
       - tox -e park
       - tox -e release
       - git clone https://github.com/aws-samples/busy-engineers-document-bucket.git

Diff for: codebuild/release/test-release.yml

@@ -1,8 +1,6 @@
 version: 0.2
 
 env:
-  variables:
-    BRANCH: "master"
   secrets-manager:
     TWINE_USERNAME: TestPyPiCryptoTools:username 
     TWINE_PASSWORD: TestPyPiCryptoTools:password
@@ -14,7 +12,8 @@ phases:
   build:
     commands:
       - pip install tox
-      - git checkout $BRANCH
+      - git fetch origin $COMMIT_ID:$COMMIT_ID --depth=1
+      - git checkout $COMMIT_ID
       - tox -e park
       - tox -e test-release