removing broken cran mirror

[lbergelson]

No description provided.

[codecov-io]

Codecov Report

Merging #5593 into master will increase coverage by 0.211%.
The diff coverage is n/a.

@@               Coverage Diff               @@
##              master     #5593       +/-   ##
===============================================
+ Coverage     86.838%   87.049%   +0.211%     
- Complexity     31439     31526       +87     
===============================================
  Files           1928      1928               
  Lines         145340    145340               
  Branches       16089     16089               
===============================================
+ Hits          126211    126517      +306     
+ Misses         13301     12963      -338     
- Partials        5828      5860       +32

Impacted Files	Coverage Δ	Complexity Δ
...nder/utils/runtime/StreamingProcessController.java	67.773% <0%> (-0.948%)	33% <0%> (-1%)
...ithwaterman/SmithWatermanIntelAlignerUnitTest.java	60% <0%> (ø)	2% <0%> (ø)	⬇️
.../hellbender/tools/genomicsdb/GenomicsDBImport.java	78.195% <0%> (+0.376%)	53% <0%> (ø)	⬇️
...stitute/hellbender/engine/spark/GATKSparkTool.java	81.921% <0%> (+1.13%)	78% <0%> (ø)	⬇️
...hellbender/utils/pairhmm/VectorLoglessPairHMM.java	86.842% <0%> (+1.316%)	12% <0%> (ø)	⬇️
...institute/hellbender/exceptions/UserException.java	66.197% <0%> (+1.408%)	3% <0%> (ø)	⬇️
...institute/hellbender/engine/FeatureDataSource.java	76.471% <0%> (+1.471%)	42% <0%> (+2%)	⬆️
...te/hellbender/engine/spark/VariantWalkerSpark.java	75% <0%> (+2.273%)	14% <0%> (ø)	⬇️
...stitute/hellbender/utils/runtime/RuntimeUtils.java	70.588% <0%> (+2.941%)	10% <0%> (ø)	⬇️
...adinstitute/hellbender/engine/ReadsDataSource.java	92.424% <0%> (+3.03%)	63% <0%> (+2%)	⬆️
... and 10 more

[droazen]

Tests pass now -- switch to a non-snapshot base image, then this can be merged