re-enables coveralls (with non-fatal failure)

A coveralls outage should not break builds. This commit proceeds with
the pipeline if a coveralls request fails.

.circleci/config.yml

@@ -63,6 +63,7 @@ jobs:
           key: v3-node12-dependencies-{{ checksum "package.json" }}
       - run: npm test -- --maxWorkers=4
       - run: npm run build
+      - run: cat coverage/lcov.info | ./node_modules/coveralls/bin/coveralls.js || true
 
   test_node14:
     docker: