omniauth 1.6.0 on Ruby Gems

Updates / Fixes

Performance benchmarks for middleware call (PR: #775)
Simplify Default Strategy Options (PR: #777)
Improve perf by using Hashie::Mash#[] (PR: #778)
Pass through test_mode with alternate request method (PR: #779)
Avoid Minitest warnings (PR: #850)
Set omniauth.headers on the request phase (PR: #806)
Set params when mocking a failure (PR: #812; Issue: #811)
docs: TestCase expects class in strategy method array (PR: #868)
Update AuthHash#regular_writer to ensure that #info is a Hash (#848)
Loosen hashie requirements to fix potential performance issues. Please define 3.4.6 in your Gemfile if you experience issues with 3.5.x. (PR: #887; Issue: #886)