setnames match to dup in colnames downgraded from error to warning

[mattdowle]

Resolves tsbox in #3581

[mattdowle]

Upload of codecov results failed with timeout error. Happens a fair bit. Low risk to proceed anyway and coverage will catch up on master anyway.

Still running (6 of 20): Rscript -e library(covr); codecov()
The command Rscript -e library(covr); codecov() exited with 1.
Log:
Error in curl::curl_fetch_memory(url, handle = handle) : 
  Timeout was reached: Connection timed out after 10000 milliseconds
Calls: codecov ... request_fetch -> request_fetch.write_memory -> <Anonymous>
Execution halted
/home/travis/.travis/functions: line 537: 14765 Terminated
    travis_jigger "${!}" "${timeout}" "${cmd[@]}"

I raised a PR a month ago to enhance the curl error message so we know the domain that is failing. So we can do something about it. jeroen/curl#191