Add some tests around Windows::RootCerts.

spec/unit/windows/root_certs_spec.rb

@@ -0,0 +1,22 @@
+require 'spec_helper'
+
+describe 'RestClient::Windows::RootCerts',
+         :if => RestClient::Windows.windows? do
+  let(:x509_store) { RestClient::Windows::RootCerts.instance.to_a }
+
+  it 'should return at least one X509 certificate' do
+    expect(x509_store.to_a).to have_at_least(1).items
+  end
+
+  it 'should return an X509 certificate with a subject' do
+    x509 = x509_store.first
+
+    expect(x509.subject.to_s).to match(/CN=.*/)
+  end
+
+  it 'should return X509 certificate objects' do
+    x509_store.each do |cert|
+      cert.should be_a(OpenSSL::X509::Certificate)
+    end
+  end
+end