Log Message:
Update ruby-net-ping to 1.7.2.

== 1.7.2 - 21-Jan-2014
* Fixed a bug in the Ping::HTTP constructor where it was not honoring the
  port if provided as the second argument. Thanks go to Florian Anderiasch
  for the spot.
* Removed win32-open3 require in the Ping::External class since it isn't
  needed in Ruby 1.9.x or later.
* Refactored the Ping::External class so that it checks the exit status rather
  than try to parse output. Thanks go to Miguel Tubia for the suggestion.
* Dropped explicit support for Windows XP.
* Removed reference to win32-open3 in README.

== 1.7.1 - 26-Sep-2013
* Fixed a bug in the Ping::TCP class where it could return nil instead
  of false. Thanks go to Grandy Nguyen for the patch.

== 1.7.0 - 25-Aug-2013
* Now requires Ruby 1.9.x or later.
* Replaced the main ping code for the Ping::TCP class. The timeout module
  really doesn't work very well with sockets, and so a raw socket approach
  combined with IO.select is now used instead.
* Updates to the doc/ping.txt file.

== 1.6.2 - 8-Aug-2013
* Fixed a bug in the ICMP ping helper module. Thanks go to Yuichi
  Tsunematsu for the spot.
* The win32-security library is not just a development dependency. Thanks
  again go to Yuichi Tsunematsu for the spot.
* Updated the icmp ping tests.
* Updated the gemspec for MS Windows.

== 1.6.1 - 17-Jul-2013
* Automatically set the scheme to "http" if not present when performing
  HTTP pings. See https://bugs.ruby-lang.org/issues/8645 for an issue
  with the uri library that led to this change. Thanks go to Preston Lee
  for the spot.
* Removed the windows/system_info dependency, since it added other
  dependencies just to check the Windows version. Instead, I added a
  helper file that adds some needed Windows functions using FFI.
* Added Rake as a development dependency and updated the Gemfile
  source because Bundler. Thanks to Jean-Philippe Doyle for the patches.
* Added some warning text to the Net::Ping::External tests for users
  who are using OpenDNS. In short, you will probably get test failures
  and surprising true results for bad hosts.

== 1.6.0 - 19-Mar-2013
* Split out the ldap portion of the code into its own branch.
* Don't require resolv-replace on Ruby 1.9.3 or later.
* Now gets proxy information from the http_proxy, https_proxy, and
  no_proxy environment variables and uses that when making requests.
  Thanks go to Kevin Olbrich for the patch.