Bump net-ldap version

Author: jonmbake

plugin.rb

@@ -7,7 +7,7 @@
 
 gem 'pyu-ruby-sasl', '0.0.3.3', require: false
 gem 'rubyntlm', '0.3.4', require: false
-gem 'net-ldap', '0.17.1'
+gem 'net-ldap', '0.18.0'
 
 require 'yaml'
 require_relative 'lib/omniauth-ldap/adaptor'