Candidate model

https://ucarecdn.com/42813974-d2b1-48ab-af22-a98366b9665f/candidate_model_added.png
Candidate list on index
Moved layout to base.html

Conflicts:

	uc_django_tutorial/templates/candidates/candidate_list.html
Candidate update view
Install Uploadcare
Added a field for resume

https://ucarecdn.com/92d56a14-d5e9-4fd1-8d61-65ee4b3e8c95/added_resume_field.png
Show whether the candidate has resume attached on index
Media for candidate update form

https://ucarecdn.com/6ccf75e7-2170-4374-964b-6a5b86e30653/upload_resume_from_dropbox.png