Migrate pods with undefined podModulePrefix

[Subtletree]

When no podModulePrefix is specified in environment.js then podModulePrefix is undefined rather than 'pods' or ''.

• Added test for app where podModulePrefix = undefined
• Added config files to pod tests

[NullVoxPopuli]

looks good -- my only concern is that existing tests were modified. why the config additions?

[Subtletree]

Previously when podModulePrefix = '', config files weren't being migrated correctly but there was no tests to catch it.

'config': {
  'foo': {
    'baz.sh': 'yolo'
  }
},

was being transformed into:

{
   config: {
+    baz.sh: "yolo"
     foo: {
-      baz.sh: "yolo"
     }
   }
 }

if (!arePodsNamespaced) {
  ...
  if (type === undefined){
    // was getting modified here
  }
}

[NullVoxPopuli]

oh ok. cool :+1:

[rwjblue]

Thank you!