LI-197586 Pin coveralls-python-action to release SHA (#68)

Replace the mutable @develop reference in ci.yml with the immutable commit
SHA of release v20201129, closing the supply-chain risk of running whatever
sits on the third-party action's develop branch (CWE-829).

Co-authored-by: brsouzapaypal <336266991+brsouzapaypal@users.noreply.github.com>

Author: brsouzapaypal

.github/workflows/ci.yml

@@ -98,4 +98,4 @@ jobs:
       - name: Coverage
         run: make coverage
 
-      - uses: AndreMiras/coveralls-python-action@develop
+      - uses: AndreMiras/coveralls-python-action@f5fd5c309b39d01599fb92c72d4f7409ea78aec9 # v20201129