Run covr on a package and output the result so it is available on Azure Pipelines

Usage

azure(
  ...,
  coverage = package_coverage(..., quiet = quiet),
  filename = "coverage.xml",
  quiet = TRUE
)

...: arguments passed to package_coverage()
coverage: an existing coverage object to submit, if NULL, package_coverage() will be called with the arguments from ...
filename: the name of the Cobertura XML file
quiet: if FALSE, print the coverage before submission.