MNT: Use the new binary Codecov uploader

Author: kernc

.github/workflows/ci.yml

@@ -57,7 +57,7 @@ jobs:
           flake8
           mypy backtesting
           time catchsegv coverage run -m backtesting.test
-          bash <(curl -s https://codecov.io/bash)
+          curl -Os https://uploader.codecov.io/v0.1.9/linux/codecov && chmod +x codecov && ./codecov -vf coverage.xml
 
       - name: Test
         if: '! matrix.test-type'