[ALOY-649] Don't put ticket-based test apps on npm

The test apps in "test/apps/testing" are critical for verifying the resolution of issues, but they are not meant to serve as examples for other developers. Take the [grammar test app](https://github.com/appcelerator/alloy/blob/master/test/apps/testing/grammar/styles/index.tss) for example, which uses horrific TSS notation in order to stress test the TSS grammar parsing. Developers should _never_ write TSS like this, but it allows the Alloy compiler in automated testing to get a full workout. We should add and entry for "test/apps/testing" in the .npmignore file so that these test are noe pushed to the npm repo, but remain resident only in the github repo.