Remove slug edit from import form.

[jkmarx]

Resolves #1629

[codecov]

Codecov Report

Merging #2473 into develop will increase coverage by 0.01%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           develop    #2473      +/-   ##
===========================================
+ Coverage    51.52%   51.53%   +0.01%     
===========================================
  Files          389      389              
  Lines        27106    27097       -9     
  Branches      1247     1245       -2     
===========================================
- Hits         13966    13965       -1     
+ Misses       13140    13132       -8

Impacted Files	Coverage Δ
...e/js/data-set-import/controllers/metadata-table.js	21.96% <ø> (+0.53%)	⬆️

---

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 b913020...361ad36. Read the comment docs.

[hackdna]

Slug handling should also be removed from the corresponding server side code, for example:

refinery-platform/refinery/data_set_manager/views.py

Line 540 in e53a8a5

slug=request.POST.get('slug'),