Return null for no-content responses with fetch

[bedeoverend]

Checks if the response is 204 when using fetch and return null body. Fixes #83

[bedeoverend]

@daffl so this isn't ready to merge yet - what I've added in has broken quite a few tests, though I'm not quite sure why or what's going on - I don't think I'm familiar enough with the tests setup.

I'm also not really satisfied with the test setup i.e. without the 'fix' the tests fail saying Expected {} === null, rather than throwing the expected error as outlined in #83. But I don't think we can get around that until node-fetch/node-fetch#165 is resolved / reverted.

[daffl]

I don't think arrow functions with brackets have an implicit return so this will probably have to be return response.json();.

[bedeoverend]

Oh wow, that's embarrassing. Yup you're exactly right, patched.

[daffl]

@bedeoverend I made a comment. I think you just need to add a return.

[bedeoverend]

Thanks @daffl - can't believe I missed that one. That's done the trick, looks all good now. Tried it out in a local project I'm working on that I discovered the bug initially in, and works well now.

[daffl]

Perfect, thank you! Released in v1.5.2. feathers-client will be updated once the tests pass.

[bedeoverend]

Sounds good. No worries - thanks for all the hard work!