Fix tests, update contributors, prepare release

[polettif]

Prepare release 1.6.1. The package is on its way to CRAN now.

• updated list of contributors in description
• removed/replaced deprecated testthat functions
• skip all tests on CRAN which read the nyc dataset
• Fix multi-thread data.table tests for CRAN on Debian

Resolving the following note was IMO unnecessary convoluted:

* checking tests ... [62s/8s] NOTE
  Running ‘testthat.R’ [62s/8s]
Running R code in ‘testthat.R’ had CPU time 7.9 times elapsed time

I found a solution here: Rdatatable/data.table#5658 as @eddelbuettel stated

package authors who each have to learn the 'how to do this' one by one

definitely applies here.

[eddelbuettel]

Yes that is good as it covers all tests globally. You could play additional dances and condition on 'knowable' states (e.g. if (Sys.info()[["sysname"]]=="Linux) may make sense) but this should work.

(Oh, and just to state the obvious in case there was any doubt: I disagree strongly with this Policy requirement but my few posts on the package development list have clearly not changed anybody's mind at CRAN so the above is chiefly a coping mechanism.)

[polettif]

ok 👍 thanks!

[polettif]

No worries, it was quite clear that you disagree with the policy decision.

I don't know enough about multithreading packages myself but I don't find the arguments made by CRAN in the R-pkg-devel list that I skimmed to be all that convincing. The way the policy is enforced however (I just learned of it because I wanted to push a really minor fix to CRAN) is, let's say, not ideal. So at this point, any coping mechanism is fine by me, I just wanted to get the package up again.