Change to pass data.table v1.12.0 please

[mattdowle]

Hi Alex,

data.table v1.12.0 is about to go to CRAN and revdep checking shows one fail in SpaDES.core. I've checked this PR passes. The 6th column of by= here is "arguments" which is type list which isn't supported by sorting/grouping/unique in data.table. It worked before because data.table didn't look at the type of the column until it needed to. In this case, the first few columns of by= were enough to establish the uniqueness and the subsequent columns weren't used. The new version of data.table works a bit differently and all the column types are now checked up-front.

The status before this PR was :

Quitting from lines 637-677 (ii-modules.Rmd) 
Error: processing vignette 'ii-modules.Rmd' failed with diagnostics:
Column 6 of by= (5) is type 'list', not yet supported
Execution halted

* checking PDF version of manual ... OK
* DONE

Status: 1 WARNING
See
  ‘/home/mdowle/build/revdeplib/SpaDES.core.Rcheck/00check.log’
for details.

Please could you update SpaDES.core on CRAN. Either in advance or after data.table is there is fine too.

Thanks, Matt

[coveralls]

Coverage decreased (-1.2%) to 73.447% when pulling c9d259e on mattdowle:master into f9696fc on PredictiveEcology:master.

[achubaty]

@eliotmcintire can you please review?

[eliotmcintire]

I think it is fine to accept PR.

[eliotmcintire]

Seems fine and appropriate

[achubaty]

change should be made in development!