Add NodeRelationships return specs.

spec/unit/rest/node_relationships_spec.rb

@@ -17,6 +17,12 @@ class Rest
         subject.create("some_type", "42", "43", {:foo => "bar", :baz => "qux"})
       end
 
+      it "returns the post results" do
+        connection.stub(:post).and_return("foo")
+
+        subject.create("some_type", "42", "43", {}).should == "foo"
+      end
+
       it "gets relationships" do
         connection.should_receive(:get).with("/node/42/relationships/all")
         subject.get("42")
@@ -37,6 +43,16 @@ class Rest
         subject.get("42", :in, ["foo", "bar"])
       end
 
+      it "returns nil if no relationships were found" do
+        connection.stub(:get).and_return(nil)
+        subject.get("42", :in).should be_nil
+      end
+
+      it "returns nil if no relationships were found by type" do
+        connection.stub(:get).and_return(nil)
+        subject.get("42", :in, "foo")
+      end
+
       context "directions" do
 
         [ :incoming, "incoming", :in, "in" ].each do |direction|