auto-deploy functions should use local variables

The following discussion from !39 (merged) should be addressed:

• @tkuah started a discussion: (+5 comments)

  I think we will also need to create secret for stable track here too.

  But actually, looking at the implementation of create_application_secret, I don't see why $track is important. Maybe we just create 1 secret for all tracks ?

In the above discussion, we discovered that most of auto-deploy is using global variables instead of local variables, leading to odd behavior when mixing function calls. All the lowercase variables should probably be local.