Many mini fixes

[statasaurus]

This will fix almost all the current issues. None of which were huge so I didn't feel like they justified their own branch.

• derivation and code list, should be able to accept empty table #16 the metacore function now accepts any empty datasets and creates an empty dataset with the correct column names and types
• yn_to_tf() should function if input variable is already boolean #10 yn function checks for logicals and returns them
• key_seq is not supported in spec_type_to_ds_vars() unless it is in an external sheet #11 updated function description to make this clearer
• format element of cols vector in spec_type_to_var_spec() only accepts 'Format' and not 'format' as the column name #12 updated regex so to [F|f]ormat so it can accept lower case
• Supp flag in DS_vars  #14 added supp_flag to ds_vars (on a side note we did a really good job with this it was super easy to change and only required a few edits)
• create_tbl should return column if exact match  #15 modified create =tbl so if there are two potential matches in the same dataset and one is an exact match it uses that

Once this is merged in do you want to submit to CRAN? it will probably fail, but it will give us another bolus of issues to tackle

[codecov]

Codecov Report

Merging #18 (4f239dc) into main (05608da) will increase coverage by 4.78%.
The diff coverage is 68.88%.

❗ Current head 4f239dc differs from pull request most recent head fb83d5b. Consider uploading reports for the commit fb83d5b to get more accurate results

@@            Coverage Diff             @@
##             main      #18      +/-   ##
==========================================
+ Coverage   79.42%   84.21%   +4.78%     
==========================================
  Files           6        6              
  Lines         802      836      +34     
==========================================
+ Hits          637      704      +67     
+ Misses        165      132      -33     

Impacted Files	Coverage Δ
R/spec_builder.R	68.85% <12.50%> (-2.10%)	⬇️
R/metacore.R	90.32% <100.00%> (+4.04%)	⬆️
R/validators.R	91.78% <100.00%> (+27.89%)	⬆️
R/xml_builders.R	94.70% <100.00%> (+0.03%)	⬆️
R/xml_helpers.R	92.42% <100.00%> (ø)

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[mstackhouse]

@statasaurus I'd like to try to fix the failures for R 3.5 and 3.6. Have you looked into those at all?

[mstackhouse]

@kodesiba since you and Christina discussed a lot of these changes, could you check out these updates?

@statasaurus can you add a NEWS.md file so we can throw the changelog up on the pkgdown too?

[statasaurus]

I didn't see an issue for this? Is it somewhere to look at?

[mstackhouse]

@statasaurus see here. Any time we merge with main we should update this and the version.

[statasaurus]

@kodesiba can you review this now? It is passing all the checks it should and I have added a news page

[kodesiba]

@statasaurus @mstackhouse everything here looks good to me. Super excited with these changes!