Added Servers for Hackers

At some point, every programmer finds themselves needing to know their way around a server.

Servers for Hackers is a newsletter for those times.
Add service discovery section and Consul.

Consul is a tool for service discovery, monitoring and configuration.
Add ZooKeeper to service discover section.

ZooKeeper is a centralized service for maintaining configuration information,
naming, providing distributed synchronization, and providing group services.
Add Doozerd to service discovery section.
Update README.md
adds Bitnami to Virtualization section
Add LeoFS to Distributed Filesystems
Adding Wireshark (Troubleshooting)
Adding suggestion for CI

Suggesting Drone as a candidate for the CI category.
Add tito to packaging
Added Horde Groupware Suite

Pehaps Horde Groupware Webmail Edition extension to the groupware suite would be nice under the Webmail section?
Docker.io
Added GitBucket
Update README.md
Added SpamAssassin to Security Tools
Moved "Dash" to correct topic
add phabricator
Add BOSH to Cloud Orchestration
Emphasise that Go is a continuous delivery server.
Add Olelo to Wikis

Olelo is a wiki that stores pages in a Git repository, supports many markup styles and has an extensible, hackable architecture!

Features:
 * Edit, move or delete pages;
 * Page attribute editor;
 * Support for hierarchical wikis (directory structure);
 * File upload;
 * History, commit and diff view;
 * Locales (Czech, English, French, German);
 * Support for many markup languages (Creole, Markdown, Textile, ...);
 * RSS/Atom changelog for whole wiki or pages; Section editing for Creole;
 * Embedded LaTeX formulas; Syntax highlighting;
 * Image resizing, SVG to PNG/JPEG conversion;
 * Auto-generated table of contents;
 * Previews;
 * View pages as S5 presentation;
 * Privacy features: Access control lists, Private wiki, Read-only wiki.