Bump ruby to version 2.3.1
Bump ruby to version 2.3.1

learningtapestry/learningregistry,CredentialEngine/CredentialRegistry,coffeejunk/CredentialRegistry,coffeejunk/CredentialRegistry,learningtapestry/learningregistry,learningtapestry/learningregistry,CredentialEngine/CredentialRegistry,CredentialEngine/CredentialRegistry,coffeejunk/CredentialRegistry