update devise_saml_authenticatable gem

[mattbaumann1]

We are still on 1.6.1 of devise_saml_authenticatable and this may cause problems given our configurations.

apokalipto/devise_saml_authenticatable#183

[jseraf]

DEPRECATION WARNING: SourceAnnotationExtractor is deprecated! Use Rails::SourceAnnotationExtractor instead. (called from <top (required)> at /Users/jds021/workspace/competitions/config/environment.rb:7)
DEPRECATION WARNING: Initialization autoloaded the constants DeviseSamlAuthenticatable::CompetitionsIdpEntityIdReader and DeviseSamlAuthenticatable::CompetitionsAttributeMapResolver.

Being able to do this is deprecated. Autoloading during initialization is going
to be an error condition in future versions of Rails.

Reloading does not reboot the application, and therefore code executed during
initialization does not run again. So, if you reload DeviseSamlAuthenticatable::CompetitionsIdpEntityIdReader, for example,
the expected changes won't be reflected in that stale Class object.

These autoloaded constants have been unloaded.

Please, check the "Autoloading and Reloading Constants" guide for solutions.
(called from <top (required)> at /Users/jds021/workspace/competitions/config/environment.rb:7)