Update faraday requirement from ~> 0.9.0 to >= 0.9, < 0.16

Updates the requirements on [faraday](https://github.com/lostisland/faraday) to permit the latest version.
- [Release notes](https://github.com/lostisland/faraday/releases)
- [Changelog](https://github.com/lostisland/faraday/blob/master/CHANGELOG.md)
- [Commits](lostisland/faraday@v0.9.0...v0.9.2)

Author: dependabot-preview[bot]

passworks.gemspec

@@ -20,7 +20,7 @@ Gem::Specification.new do |spec|
   spec.test_files    = spec.files.grep(%r{^(test|spec|features)/})
   spec.require_paths = ["lib"]
 
-  spec.add_dependency 'faraday', '~> 0.9.0'
+  spec.add_dependency 'faraday', '>= 0.9', '< 0.16'
   spec.add_dependency 'faraday_middleware', '~> 0.9.1'
 
   spec.add_development_dependency "bundler", "~> 2.0"