Remap launch.json variables

[johnthepink]

I think it will make everything less confusing and more manageable if we aren't mapping launch variables directly to variables in dependencies. We should define the launch.json in a way that is understandable, and then map them to their dependency counterparts inside of launch.

I propose we prepend all variables with LAUNCH_, and then name the variables things that make more sense to the end user.

{
  "LAUNCH_APP_NAME": "",
  "LAUNCH_APP_IDENTIFIER": "",
  "LAUNCH_APPLE_ID": "",
  "LAUNCH_APPLE_PASSWORD": "",
  "LAUNCH_KEYCHAIN_PASSWORD": "",
  "LAUNCH_IOS_CERT_PATH": "",
  "LAUNCH_IOS_CERT_PASSWORD": "",
  "LAUNCH_SLACK_URL": "",
  "LAUNCH_SLACK_ROOM": "",
  "LAUNCH_ANDROID_STORE_KEY": "",
  "LAUNCH_ANDROID_STORE_PASS": "",
  "LAUNCH_ANDROID_ZIPALIGN": "",
  "LAUNCH_IOS_HOCKEY_TOKEN": "",
  "LAUNCH_ANDROID_HOCKEY_TOKEN": "",
  "LAUNCH_ANDROID_HOCKEY_ID": "",
  "LAUNCH_PLAY_AUTH_FILE": "",
  "LAUNCH_GALAXY_DEPLOY_HOSTNAME": "",
  "LAUNCH_GALAXY_SESSION_FILE": ""
}

We can take this, and remap them as necessary inside of launch. This will avoid most conflicts with other tools and their environment variables. But, it does feel a little verbose.

We could also prepend LAUNCH_ to each variable when launch reads the file. This way, we avoid conflicts with other tools, and become a little more succinct. However, I think this would make it a little more confusing to override the variables in a CI environment.