Log Message:
Update ruby-net-ldap to 0.12.1.

=== Net::LDAP 0.12.1

* Whitespace formatting cleanup
  {#236}[https://github.com/ruby-ldap/ruby-net-ldap/pull/236]
* Set operation result if LDAP server is not accessible
  {#232}[https://github.com/ruby-ldap/ruby-net-ldap/pull/232]

=== Net::LDAP 0.12.0

* DRY up connection handling logic
  {#224}[https://github.com/ruby-ldap/ruby-net-ldap/pull/224]
* Define auth adapters
  {#226}[https://github.com/ruby-ldap/ruby-net-ldap/pull/226]
* add slash to attribute value filter
  {#225}[https://github.com/ruby-ldap/ruby-net-ldap/pull/225]
* Add the ability to provide a list of hosts for a connection
  {#223}[https://github.com/ruby-ldap/ruby-net-ldap/pull/223]
* Specify the port of LDAP server by giving INTEGRATION_PORT
  {#221}[https://github.com/ruby-ldap/ruby-net-ldap/pull/221]
* Correctly set BerIdentifiedString values to UTF-8
  {#212}[https://github.com/ruby-ldap/ruby-net-ldap/pull/212]
* Raise Net::LDAP::ConnectionRefusedError when new connection is
  refused. {#213}[https://github.com/ruby-ldap/ruby-net-ldap/pull/213]
* obscure auth password upon #inspect, added test, closes #216
  {#217}[https://github.com/ruby-ldap/ruby-net-ldap/pull/217]
* Fixing incorrect error class name
  {#207}[https://github.com/ruby-ldap/ruby-net-ldap/pull/207]
* Travis update {#205}[https://github.com/ruby-ldap/ruby-net-ldap/pull/205]
* Remove obsolete rbx-19mode from Travis
  {#204}[https://github.com/ruby-ldap/ruby-net-ldap/pull/204]
* mv "sudo" from script/install-openldap to .travis.yml
  {#199}[https://github.com/ruby-ldap/ruby-net-ldap/pull/199]
* Remove meaningless shebang
  {#200}[https://github.com/ruby-ldap/ruby-net-ldap/pull/200]
* Fix Travis CI build
  {#202}[https://github.com/ruby-ldap/ruby-net-ldap/pull/202]
* README.rdoc: fix travis link
  {#195}[https://github.com/ruby-ldap/ruby-net-ldap/pull/195]