Add silence parameter for curl when calling codecov.sh

Author: zobo

appveyor.yml

@@ -51,4 +51,4 @@ after_test:
       Remove-Item -Recurse -Force vendor
       $env:PATH = 'C:\msys64\usr\bin;' + $env:PATH
       Invoke-WebRequest -Uri 'https://codecov.io/bash' -OutFile codecov.sh
-      bash codecov.sh -f 'coverage/coverage.xml'
+      bash codecov.sh -f 'coverage/coverage.xml' -U "-s" -A "-s"