Stub file writing in tests

spec/gitlab_keys_spec.rb

@@ -53,6 +53,9 @@ describe GitlabKeys do
       File.read(tmp_authorized_keys_path).should == "existing content\n#{other_line}\n"
     end
 
+    context "without file writing" do
+      before { Tempfile.stub(:open) }
+
       it "should log an rm-key event" do
         $logger.should_receive(:info).with('Removing key key-741')
         gitlab_keys.send :rm_key
@@ -62,11 +65,13 @@ describe GitlabKeys do
         gitlab_keys.send(:rm_key).should be_true
       end
     end
+  end
 
   describe :clear do
     let(:gitlab_keys) { build_gitlab_keys('clear') }
 
     it "should return true" do
+      gitlab_keys.stub(:open)
       gitlab_keys.send(:clear).should be_true
     end
   end