Add chunked-upload migration.

[jkmarx]

Resolves #2615

[codecov]

Codecov Report

Merging #2624 into develop will decrease coverage by 0.04%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           develop   #2624      +/-   ##
==========================================
- Coverage    55.04%     55%   -0.05%     
==========================================
  Files          400     400              
  Lines        25720   25696      -24     
  Branches      1242    1242              
==========================================
- Hits         14157   14133      -24     
  Misses       11563   11563

Impacted Files	Coverage Δ
...grations/chunked_upload/0003_auto_20180226_2126.py	100% <100%> (ø)	⬆️
refinery/user_files_manager/tests.py	100% <0%> (ø)	⬆️

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