Update ipaddr_extensions dependency

On May 20 2013 1.0.0. version of `ipaddr_extensions` gem has been released.
All previous versions has been yanked.
Here is [prooflink](http://github.com).

There is some issue with version comparison of that gem.
`ipaddr_extensions` didn't use to use semversion. 

If specversion is `>= 1.0.0`, on node (which has version like `2012.1.13`) will be ok, but another node (which hasn't such  a gem) will fail.
So I propose to use `-> 1.0.0`.