Doctests for BinaryArray and LargeBinaryArray.

[novemberkilo]

Which issue does this PR close?

Closes #301.

What changes are included in this PR?

Doctests for BinaryArray and LargeBinaryArray

Are there any user-facing changes?

No.

// @alamb

[codecov-commenter]

Codecov Report

Merging #625 (e17ff0d) into master (87d2840) will increase coverage by 0.07%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #625      +/-   ##
==========================================
+ Coverage   82.41%   82.48%   +0.07%     
==========================================
  Files         167      167              
  Lines       46232    46452     +220     
==========================================
+ Hits        38100    38315     +215     
- Misses       8132     8137       +5     

Impacted Files	Coverage Δ
arrow/src/array/array_binary.rs	92.23% <ø> (ø)
parquet/src/arrow/arrow_array_reader.rs	77.65% <0.00%> (-0.47%)	⬇️
arrow/src/ipc/writer.rs	86.22% <0.00%> (-0.46%)	⬇️
arrow/src/buffer/ops.rs	96.77% <0.00%> (-0.20%)	⬇️
arrow/src/ipc/reader.rs	84.21% <0.00%> (-0.10%)	⬇️
arrow/src/compute/util.rs	97.80% <0.00%> (-0.05%)	⬇️
arrow/src/array/ord.rs	63.33% <0.00%> (ø)
arrow-flight/src/utils.rs	0.00% <0.00%> (ø)
arrow/src/array/array_union.rs	89.26% <0.00%> (ø)
arrow/src/compute/kernels/cast.rs	94.53% <0.00%> (ø)
... and 7 more

---

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 87d2840...e17ff0d. Read the comment docs.

[alamb]

Looks great -- thank you @novemberkilo ❤️