update individual role secrets from infrastructure roles (#206)

* Track origin of roles.

* Propagate changes on infrastructure roles to corresponding secrets.

When the password in the infrastructure role is updated, re-generate the
secret for that role.

Previously, the password for an infrastructure role was always fetched from
the secret, making any updates to such role a no-op after the corresponding
secret had been generated.

pkg/controller/util_test.go

@@ -131,6 +131,7 @@ func TestGetInfrastructureRoles(t *testing.T) {
 			map[string]spec.PgUser{
 				"testrole": {
 					Name:     "testrole",
+					Origin:   spec.RoleOriginInfrastructure,
 					Password: "testpassword",
 					MemberOf: []string{"testinrole"},
 				},