Change BFInfo to use fields option of packageDescription()

[elinw]

BFInfo is currently causing an error on some builds of the effectsize package.

https://cloud.r-project.org/web/checks/check_results_effectsize.html

Quitting from xtabs.Rmd:207-215 [unnamed-chunk-13]
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  <error/rlang_error>
  Error in `packageDescription("BayesFactor")$Version`:
  ! $ operator is invalid for atomic vectors
  ---
  Backtrace:
      ▆
   1. └─BayesFactor::contingencyTableBF(RCT_table, sampleType = "jointMulti")
   2.   └─BayesFactor:::BFcontingencyTable(...)
   3.     ├─methods::new(...)
   4.     │ ├─methods::initialize(value, ...)
   5.     │ └─methods::initialize(value, ...)
   6.     └─BayesFactor::BFInfo(FALSE)
   7.       └─base::paste(packageDescription("BayesFactor")$Version)
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  
  Error: processing vignette 'xtabs.Rmd' failed with diagnostics:
  $ operator is invalid for atomic vectors

This can be resolved by using the fields option of packageDescription().

packageDescription("BayesFactor", fields = "Version")

rather than the $ notation.

[richarddmorey]

Thanks - I'll check this out very soon.