relax faraday and faraday_middleware dependency

[ashkulz]

This was blocking us from upgrading to faraday 1.0

[Willardgmoore]

I should have checked other PR's before adding mine. @ashkulz Did you run tests or anything? Idk if that would help them approve the PR any sooner.

[ashkulz]

TravisCI reports a failure on account of CVE-2020-8130, need to specify rake >= 12.3.3. Everything works for our limited usage with this PR, so I didn't really check further 🤷‍♂️

[Willardgmoore]

If this pr doesn't get accepted soon then I might just use your fork for now in my gemfile

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
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[waghanza]

I've made #25, maybe we can combine our efforts