Fix compatibility with Faraday 1.0

[yuki24]

This PR adds a build matrix for Faraday 1.0 and fixes the failing specs.

[zenspider]

This broke inspec/inspec as well. We aliased the old namespacing over to the new namespacing as a workaround. It's just a 1-liner and might be easier to swallow than this PR:

inspec/inspec@984e02e

We'd really like SOME fix to be upstream from us tho. This will start to affect more and more and Gemfiles get bumped in CIs. Especially confusing since it was faraday that bumped, not faraday_middleware.

[glaszig]

would somebody please merge/fix and release? thank you.

[bastelfreak]

Hi people. Since faraday 1.0 is out, could one of the maintainers have a look here?

[oshow]

Why spec are failing:
In faraday 1.0, this env[:body] refers to request_body, because status has not yet been set here.

faraday_middleware/spec/unit/follow_redirects_spec.rb

Line 52 in be68541

body = env[:body] and body.empty? && (body = nil)

[iMacTia]

I'm closing this in favour of #196 which goes for a different approach: FaradayMiddleware v1.0 will be compatible with Faraday 1.0 (I'll try to make it compatible with Faraday 0.17.x as well, but that remains to be seen