Make file_line default to ensure => present

The examples in the file_line resource documentation state the following
resource should work:

    file_line { 'sudo_rule':
      path => '/etc/sudoers',
      line => '%sudo ALL=(ALL) ALL',
    }

Without this patch the example does not work because ensure is not set
to present.

This patch fixes the problem by setting the default value of ensure to
present.

Author: Jeff McCune

lib/puppet/type/file_line.rb

@@ -23,18 +23,20 @@
 
   EOT
 
-  ensurable
+  ensurable do
+    defaultto :present
+  end
 
   newparam(:name, :namevar => true) do
-    desc 'arbitrary name used as identity'
+    desc 'An arbitrary name used as the identity of the resource.'
   end
 
   newparam(:line) do
-    desc 'The line to be appended to the path.'
+    desc 'The line to be appended to the file located by the path parameter.'
   end
 
   newparam(:path) do
-    desc 'File to possibly append a line to.'
+    desc 'The file Puppet will ensure contains the line specified by the line parameter.'
     validate do |value|
       unless (Puppet.features.posix? and value =~ /^\//) or (Puppet.features.microsoft_windows? and (value =~ /^.:\// or value =~ /^\/\/[^\/]+\/[^\/]+/))
         raise(Puppet::Error, "File paths must be fully qualified, not '#{value}'")

spec/unit/puppet/type/file_line_spec.rb

@@ -21,4 +21,7 @@
   it 'should require that a file is specified' do
     expect { Puppet::Type.type(:file_line).new(:name => 'foo', :line => 'path') }.should raise_error(Puppet::Error, /Both line and path are required attributes/)
   end
+  it 'should default to ensure => present' do
+    file_line[:ensure].should eq :present
+  end
 end