Create unit tests for Issue #50 (ExtractPopularImages)

[greebie]

Unit Test Cover for Issue #50

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GitHub issue(s):

#50

What does this Pull Request do?

Increases test coverage.

How should this be tested?

Travis & Codecov

Additional Notes:

NA

Interested parties

Tag (@ mention) interested parties.

Thanks in advance for your help with the Archives Unleashed Toolkit!

[codecov]

Codecov Report

Merging #93 into master will increase coverage by 2.19%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master      #93      +/-   ##
==========================================
+ Coverage   55.66%   57.85%   +2.19%     
==========================================
  Files          41       41              
  Lines         821      821              
  Branches      146      146              
==========================================
+ Hits          457      475      +18     
+ Misses        320      296      -24     
- Partials       44       50       +6

Impacted Files	Coverage Δ
...ala/io/archivesunleashed/spark/rdd/RecordRDD.scala	38.88% <0%> (+1.85%)	⬆️
...nleashed/spark/matchbox/ExtractPopularImages.scala	100% <0%> (+100%)	⬆️
.../archivesunleashed/spark/matchbox/ComputeMD5.scala	100% <0%> (+100%)	⬆️

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