SAML support (#3494)

* PLT-3073: Implement SAML/Okta Server side (EE) (#3422)

* PLT-3137 Support for SAML configuration

* PLT-3410 SAML Database Store

* PLT-3411 CLI to add Identity Provider Certificate and Service Provider Private Key

* PLT-3409 SAML Interface for EE

* PLT-3139 Handle SAML authentication server side

* Add localization messages

* PLT-3443 SAML Obtain SP metadata

* PLT-3142 Login & Switch to/from SAML

* Remove Certs for Database & Clean SAML Request

* Make required Username, FirstName and LastName

* PLT-3140 Add SAML to System Console (#3476)

* PLT-3140 Add SAML to System Console

* Move web_client functions to client.jsx

* Fix issues found by PM

* update package.json mattermost driver

* Fix text messages for SAML

glide.lock

@@ -42,6 +42,8 @@ imports:
   version: 9c19ed558d5df4da88e2ade9c8940d742aef0e7e
 - name: github.com/gorilla/websocket
   version: 1f512fc3f05332ba7117626cdfb4e07474e58e60
+  - name: github.com/kardianos/osext
+    version: 29ae4ffbc9a6fe9fb2bc5029050ce6996ea1d3bc
 - name: github.com/lib/pq
   version: ee1442bda7bd1b6a84e913bdb421cb1874ec629d
   subpackages: