Polyfill to nicolaslopezj:roles for alanning:roles

In place upgrade kit for moving from alanning:roles meteor package to nicolaslopezj:roles.

Include unit tests and migration scripts.

Schema migration

alanning:roles store roles in users collection with roles field object of group id for roles. An example user record

{
  "_id": "qx4RqmpJsZxfxA8bj",
  "roles": {
    "wCvSS2exrrGyZndYb": [
      "read",
      "write",
      "manage"
    ]
  }
}

On nicolaslopezj:roles, each of these roles becomes action, for example:

{
    userId: qx4RqmpJsZxfxA8bj, 
    roles: [
      canvas.read, 
      canvas.write, 
      canvas.manage
    ]
}

alanning:roles keeps list of roles in roles collection, while nicolaslopezj:roles just keep roles, actions in memory. There wCvSS2exrrGyZndYb is name of the Role and wCvSS2exrrGyZndYb.read, etc are actions.