Significant set of changes

* Use /join and /leave instead of roles
* Use scopes to check for user rights rather than using the config file
* Add /list to show the set of current people signed up
* Add a bunch more testing for various things
* Version both the config and the state

config.py

@@ -1,38 +1,77 @@
 """Very simple config loading library"""
 from schema import Schema, And, Use
 import files
+import os
+import logging
+
+logger = logging.getLogger("config")
+logger.setLevel(logging.INFO)
 
 _FILE = "config.json"
+
+# Warning: Changing any of the below needs proper thought to ensure backwards compatibility
+_VERSION = 1
+
+
+class _Keys():
+    TOKEN = "token"
+    VERSION = "version"
+
+    # Removed
+    OWNERS = "owners"
+
+
 _SCHEMA = Schema(
     {
-        # Discord bot token
-        "token": And(Use(str)),
+        # The current version
+        _Keys.VERSION: And(Use(int)),
 
-        # ids of owners authorised to use owner-only commands
-        "owners": And(Use(list[int])),
+        # Discord bot token
+        _Keys.TOKEN: And(Use(str)),
     }
 )
 
 
+def _migrate_to_v1(d: dict):
+    # Owners moved to History in v1
+    # Note: owners will be required to be re-added to the state.json
+    owners = d.pop(_Keys.OWNERS)
+    logger.warn(
+        "Migration removed owners from config, these must be re-added to the state.json")
+    logger.warn("Owners: %s", owners)
+
+
+# Set of migration functions to apply
+_MIGRATIONS = [
+    _migrate_to_v1
+]
+
+
 class Config():
     def __init__(self, data: dict):
         """Initialise and validate the config"""
         _SCHEMA.validate(data)
-        self.__dict__ = data
+        self._dict = data
 
     @property
     def token(self) -> str:
-        return self.__dict__["token"]
-
-    @property
-    def owners(self) -> list[int]:
-        return self.__dict__["owners"]
-
-    def reload(self) -> None:
-        """Reload the config back into the dict"""
-        self.__dict__ = load().__dict__
+        return self._dict["token"]
 
 
-def load() -> Config:
-    """Load the config"""
-    return Config(files.load(_FILE))
+def _migrate(dict: dict):
+    """Migrate a dict through versions"""
+    version = dict.get("version", 0)
+    for i in range(version, _VERSION):
+        _MIGRATIONS[i](dict)
+        dict["version"] = _VERSION
+
+
+def load_from_file(file: str = _FILE) -> Config:
+    """
+    Load the state from a file
+    Apply any required migrations
+    """
+    assert os.path.isfile(file)
+    loaded = files.load(file)
+    _migrate(loaded)
+    return Config(loaded)