refactor test CdnFacadeTest
refactor test CdnFacadeTest

rename testPreparePathThrowsExceptionWhenEmptyParameter to
testUrlGeneratorThrowsException

related to commit #6a0ed63b22c20e3117c4e35c8b2f35e8926b4ccf

gantir/cdn,londoh/cdn,Vinelab/cdn,luanli22/cdn