Added dependencies for rubygems

ruby/manifests/init.pp

@@ -7,8 +7,17 @@ class ruby::rubygems {
     require gcc
     require gnu::make
 
-    package { "rubygems":
+    package { "ruby-devel":
         ensure => installed,
+        name   => $operatingsystem ? {
+            "ubuntu" => regsubst($rubyversion, '^([0-9]+\.[0-9]+)\..*', 'ruby\1-dev'),
+            default  => "ruby-devel",
+        },
+    }
+
+    package { "rubygems":
+        ensure  => installed,
+        require => Package["ruby-devel"],
     }
 
 }