Fix deprecations with nt.names and kw.data

[JeffFessler]

Addresses #200

[codecov]

Codecov Report

Merging #201 (b13994c) into master (bf961cf) will decrease coverage by 0.13%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #201      +/-   ##
==========================================
- Coverage   89.45%   89.31%   -0.14%     
==========================================
  Files           7        7              
  Lines         673      674       +1     
==========================================
  Hits          602      602              
- Misses         71       72       +1     

Impacted Files	Coverage Δ
src/indexing.jl	82.51% <ø> (-0.46%)	⬇️
src/core.jl	87.95% <100.00%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update bf961cf...b13994c. Read the comment docs.

[johnnychen94]

Sorry for the delay! I'll go through other PRs later tonight and make a patch release.