Fixup use of conditional pending

Without this patch the tests aren't actually getting marked as pending
because exceptions are being raised in the before blocks.  This patch
addresses the problem by switching the declaration references to a lazy
evaluated let method rather than a preemptive before block.  This
prevents the exception and allows the pending methods to execute.

spec/unit/network/authstore_spec.rb

@@ -300,16 +300,17 @@
     "::2:3:4:5:6:7:8",
   ].each { |ip|
     describe "when the pattern is a valid IP such as #{ip}" do
-      before :each do
-        @declaration = Puppet::Network::AuthStore::Declaration.new(:allow_ip,ip)
+      let(:declaration) do
+        Puppet::Network::AuthStore::Declaration.new(:allow_ip,ip)
       end
+
       it "should match the specified IP" do
         pending "resolution of ruby issue [7477](http://goo.gl/Bb1LU)", :if => ruby_bug_7477
-        @declaration.should be_match('www.testsite.org',ip)
+        declaration.should be_match('www.testsite.org',ip)
       end
       it "should not match other IPs" do
         pending "resolution of ruby issue [7477](http://goo.gl/Bb1LU)", :if => ruby_bug_7477
-        @declaration.should_not be_match('www.testsite.org','200.101.99.98')
+        declaration.should_not be_match('www.testsite.org','200.101.99.98')
       end
     end
   }