add MS oauth

lib/users.rb

@@ -4,12 +4,21 @@ module Users
   module_function
 
   def from_omniauth(oauth)
-    user = User.find_by(email: oauth.info.email)
+    user = User.find_by(email: oauth.info.email.to_s.downcase)
 
     return user if user
 
-    User.new(email: oauth.info.email,
-             first_name: oauth.extra.id_info.given_name,
-             last_name: oauth.extra.id_info.family_name)
+    case oauth['provider'].to_s
+    when 'google_oauth2'
+      User.new(email: oauth.info.email,
+               first_name: oauth.extra.id_info.given_name,
+               last_name: oauth.extra.id_info.family_name)
+    when 'microsoft_office365'
+      User.new(email: oauth.info.email,
+               first_name: oauth.info.first_name,
+               last_name: oauth.info.last_name)
+    when 'github'
+      User.new(email: oauth.info.email, first_name: oauth.info.name)
+    end
   end
 end