ui: Delete a project button for owners of project

[odscjames]

https://github.com/OpenDataServices/standards-lab/issues/141

Also,

• check permissions server side when deleting data files
• Send a non 200 response for any API errors

This JS code also checks response for non-200 See #134

[odscjames]

Note this makes all API failures have a non 200 status code, generally good practice and something we need for #134 anyway

[coveralls]

Pull Request Test Coverage Report for Build 989388338

• 8 of 17 (47.06%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.6%) to 70.776%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
standards_lab/api/views.py	8	17	47.06%
<!--	Total:	8	17	47.06%	-->

Totals
Change from base Build 895759267:	-0.6%
Covered Lines:	465
Relevant Lines:	657

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💛 - Coveralls