Dynamic configuration of http headers

[viniciussoares]

Allow http headers to be reconfigured through HTTPNetworkTransport.

This will probably resolve the following issues:

#37
#140
#131 (Never been merged)

---

/enhancement

• feature
• blocking
• docs

[apollo-cla]

@viniciussoares: Thank you for submitting a pull request! Before we can merge it, you'll need to sign the Meteor Contributor Agreement here: https://contribute.meteor.com/

[amol-c]

Can we get this PR merged as a temporary fix even if there are plan for longer term fix?

[viniciussoares]

@amol-c as a temporary workaround update your Podfile to use my repository.

pod 'Apollo',        git: 'https://github.com/viniciussoares/apollo-ios', branch: 'master'
pod 'Apollo/SQLite', git: 'https://github.com/viniciussoares/apollo-ios', branch: 'master'

[rajkhatri]

You have 2 extra spaces before request for consistent indentation

[brennantaylor]

Could we instead get a delegate? This would make per-request headers much easier (ie per request signing) and make it more extensible to other changes or instrumentation for any part of the http request before it is fired off.

[martijnwalraven]

I agree with @brennantaylor that adding a property for headers won't be flexible enough to support the use cases that have come up. I added some more detail about this in #297 (comment).

[viniciussoares]

I agree :) Closed in favor of #297

[brennantaylor]

@viniciussoares Thanks, your PR inspired me to get off my butt and open one of my own :p