Link account id with the external user store (#184)

* get account id from access token claim

* use GetOrCreateAccountByUser and add test

* correct account id claim

* remove unused account

* Idp manager interface

* auth0 idp manager

* use if instead of switch case

* remove unnecessary lock

* NewAuth0Manager

* move idpmanager to its own package

* update metadata when accountId is not supplied

* update tests with idpmanager field

* format

* new idp manager and config support

* validate if we fetch the interface before converting to string

* split getJWTToken

* improve tests

* proper json fields and handle defer body close

* fix ci lint notes

* documentation and proper defer position

* UpdateUserAppMetadata tests

* update documentation

* ManagerCredentials interface

* Marshal and Unmarshal functions

* fix tests

* ManagerHelper and ManagerHTTPClient

* further tests with mocking

* rename package and custom http client

* sync local packages

* remove idp suffix

go.sum

@@ -148,7 +148,6 @@ github.com/golang/mock v1.4.1/go.mod h1:UOMv5ysSaYNkG+OFQykRIcU/QvvxJf3p21QfJ2Bt
 github.com/golang/mock v1.4.3/go.mod h1:UOMv5ysSaYNkG+OFQykRIcU/QvvxJf3p21QfJ2Bt3cw=
 github.com/golang/mock v1.4.4/go.mod h1:l3mdAwkq5BuhzHwde/uurv3sEJeZMXNpwsxVWU71h+4=
 github.com/golang/mock v1.5.0/go.mod h1:CWnOUgYIOo4TcNZ0wHX3YZCqsaM1I1Jvs6v3mP3KVu8=
-github.com/golang/mock v1.6.0 h1:ErTB+efbowRARo13NNdxyJji2egdxLGQhRaY+DUumQc=
 github.com/golang/mock v1.6.0/go.mod h1:p6yTPP+5HYm5mzsMV8JkE6ZKdX+/wYM6Hr+LicevLPs=
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/golang/protobuf v1.3.1/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=