Changed status code returned by tasks exports to be coherent with what will return users export
Added user list export in json and csv formats
Refs PyBossa/pybossa@0d74b9648e0c2788921ecd85715d701d6ea41d55 updates in GUI
Merge branch 'master' into download-user-list-issue-608

* master:
  Use new theme
  New theme
  Remove old theme
  Removed prints and reduced needlessly high number of tasks in one test at test_sched.py
  Deleted comments in test_token
  Removed non-used url variable from test_hateoas.py, referencing task exports
  Changed wrong comments in test_web.py
  Added print statements to find out more about #669
  Deleted comments in test_token
  Removed non-used url variable from test_hateoas.py, referencing task exports
  Changed wrong comments in test_web.py
Added test to test_admin.py
Added test cases to test_admin.py
Renumbered tests in  test_admin.py
Added users list check to test that checks for buttons for available actions in admin view
Modified admin documentation: added user list download
Added tests for validating json and csv users export
trick
Merge branch 'master' into download-user-list-issue-608

* master:
  Update documentation
  Unwire apps_per_page and make it an option in the settings. Closes #681
  Fix missing category
  Revert
  Add 20 featured apps to front page.
  Fix get_featured (category arg removed).
  Pass 20 apps per category to front page.
  Pass categories to front page
  Get latest changes
  Modified token auth tests to use mocks and request context
  Refactor
  Fixes: added back some imports badly deleted in previous commit
  Fixed missing return
  Refactor: extracted function for mock creation
  Fixed some bugs. Added context to remaining taskrun auth tests
  Fixed bad mistake; test had a typo and was not testing anything plus testname typo
  Modified unclear test docstrings
Changed submodule
Merge branch 'master' into download-user-list-issue-608
Merge pull request #706 from PyBossa/download-user-list-issue-608

Download user list closes #608