Make tests a little less flaky

[Jauntbox]

Related issues
N/A

Describe the proposed solution
Relaxing tolerances, and reducing random data size in a few cases so that some tests are faster and less prone to random failure.

Describe alternatives you've considered
N/A

Additional context
N/a

[codecov]

Codecov Report

Merging #221 into master will increase coverage by 9.15%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #221      +/-   ##
==========================================
+ Coverage   77.21%   86.36%   +9.15%     
==========================================
  Files         310      310              
  Lines       10137    10137              
  Branches      347      347              
==========================================
+ Hits         7827     8755     +928     
+ Misses       2310     1382     -928

Impacted Files	Coverage Δ
...ala/com/salesforce/op/features/types/package.scala	52.17% <0%> (+0.72%)	⬆️
...rce/op/stages/impl/feature/PhoneNumberParser.scala	100% <0%> (+1.29%)	⬆️
...rce/op/stages/impl/preparators/SanityChecker.scala	91.84% <0%> (+1.9%)	⬆️
...a/com/salesforce/op/readers/JoinedDataReader.scala	94.23% <0%> (+1.92%)	⬆️
...esforce/op/stages/impl/feature/TextTokenizer.scala	100% <0%> (+2.04%)	⬆️
.../salesforce/op/stages/impl/tuning/DataCutter.scala	95.65% <0%> (+2.17%)	⬆️
...op/stages/impl/regression/OpXGBoostRegressor.scala	18.18% <0%> (+2.27%)	⬆️
...p/evaluators/OpBinaryClassificationEvaluator.scala	82.5% <0%> (+2.5%)	⬆️
...ala/com/salesforce/op/dsl/RichNumericFeature.scala	100% <0%> (+2.56%)	⬆️
.../main/scala/com/salesforce/op/OpWorkflowCore.scala	93.54% <0%> (+3.22%)	⬆️
... and 54 more

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[salesforce-cla]

Thanks for the contribution! It looks like @Jauntbox is an internal user so signing the CLA is not required. However, we need to confirm this.