Initial version

This is a Go program which can synchronize Graylog 4 roles and access
privileges to dashboards and streams from a LDAP directory, based on a
YAML configuration file that maps LDAP groups to Graylog privileges.

The code is rather ugly, some features are half-baked (LDAP TLS
support, impossible to disable HTTP TLS checks, bad error handling...)
and some documentation needs to be added but it's a start.

.gitignore

@@ -0,0 +1,3 @@
+go.sum
+graylog-groups.yml
+glgroups