0.4.2
* Added `citrix_netscaler_version_history()`
* Fixed a cpl functions that use scraping (sites changed HTML)
* Added caching/refresh capability to mysql and etcd given how expensive they are to compute

0.4.1
* Improved Exim version history retriever 

0.4.0
* Add Exim version history retriever
* Improved Apache & nginx version retriever functions

0.3.0
* Significant improvements to Apache and nginx version retrievers
* Swapped out as_tibble for as_data_frame
* MIT license

0.2.2
* Support for ISC BIND

0.2.1
* Support for etcd

0.2.0
* Support for PHP

0.1.0 
* Initial release
* Support for Apache httpd, Apple iOS, Google Chrome lighttpd, memcached, mongodb, nginx, 
  mysql, openresty, openssh, sendmail and sqlite