use gemspec for bundler

Gemfile

@@ -1,10 +1,3 @@
 # Generated from /Users/kolbrich/Projects/6fusion/net-ping/net-ping.gemspec
-source :gemcutter
-gem "net-ldap", "~> 0.2.2"
-gem "ffi", ">= 1.0.0"
 
-group :development do
-  gem "test-unit", ">= 2.5.0"
-  gem "fakeweb", ">= 1.3.0"
-  gem "fakeldap", "~> 0.0.1"
-end
+gemspec