Modification of deleting cache

Added delete of the full cache of the specs. The children of the specs.js cache are now also deleted.

Now the test run correctly after every save of the files. So yo're able to use it in a watch().
But not the children(files added by the require in the testfiles) of this file. This way the required files are not deleted from the cache. This will make it impossible to run the same test twice without restarting gulp.