Store the app ID inside a JSON file which need not be added to Git

[icyflame]

The App ID on Ionic Cloud is related to the developer's account, and when multiple developers are working on the same Ionic app, and all of them are using Ionic View, if one dev changes the app's ionic.config.json file with their app_id.

Then, when this is pulled by everyone else, their own app IDs are overwritten / lost (Generally, on a simple git rebase origin/master, it will generate a conflict which now needs to be fixed before the rebase can be completed, which is a further irritation)

Of course, ionic upload fails, until you replace the app_id with the one on your account, or replace it with an empty string leading to creation of a new app on Ionic cloud.

So, the proposed method to solve this is:

1. if creating the app ID for the first time, instead of writing it to the ionic.config.json project file, store it in the .app_id.json file
2. If this file exists in the appDirectory, then infer app_id from there instead of the project file
3. Inferring app_id from project file would still be there, but this file .app_id.json would take precedence over that

I will send a patch if you are interested in this feature. I am working on an Ionic Open source app and this has been a major problem that I have been facing, and I think a lot of other people would have faced too, considering how Git works.