Fix 1836

[antgonza]

• make both lists start with 5 element
  Fixed via datatables config
• filter user study list to not contain public studies
  Fixed in qiita_pet/handlers/study_handlers/listing_handlers.py by removing public studies from the list
• check why everything in the user study list is awaiting approval
  This one was trickier than expected: (1) there was an error in the SQL, we were retrieving all available statuses vs. all statuses of all the artifacts in that study; and (2) the infer_status method was expecting a list of list with one string element but it really returned a list of strings, we were comparing against the first letter. Had to change some of the tests.

Note that this was tested in the test environment and it works as expected, still deploy if you want to take a look.

[coveralls]

Coverage decreased (-0.06%) to 84.454% when pulling 59f0ba3 on antgonza:fix-1836 into 4b74d51 on biocore:master.

[ElDeveloper]

It all looks good to me! Just kinda surprised that none of the tests changed with the changes to util.py. 👍