Update gemspec to correctly set the require_paths

ruby-2.1.x and probably previous ships with
rubygems 2.2.2 and below
which contans a bug where require_paths
cannot be appended to
this was fixed with ruby-gems pull request 909
https://github.com/rubygems/rubygems/pull/909
work-around issue by getting the array, appending
and then setting it back
Release 1.0.12

Bump the version number and update the CHANGELOG