Initial karma plugin

karma.plug

+[Core]
+name = Karma
+module = karma
+
+[Documentation]
+description = Karma service
+
+[Python]
+version = 3
+
+[Errbot]
+

karma.py

+from collections import defaultdict
+
+from errbot import BotPlugin, botcmd
+
+
+class Karma(BotPlugin):
+    """Karma service"""
+
+    def activate(self):
+        super().activate()
+
+        try:
+            self.karma = self['karma']
+        except KeyError:
+            self.karma = self['karma'] = defaultdict(int)
+
+    @botcmd
+    def karma_add(self, message, args):
+        """Adds karma"""
+        self.karma[args] += 1
+        return "Karma for {} is now {}".format(args, self.karma[args])
+
+    @botcmd
+    def karma_remove(self, message, args):
+        """Removes karma"""
+        self.karma[args] -= 1
+        return "Karma for {} is now {}".format(args, self.karma[args])     
+
+    @botcmd
+    def karma(self, message, args):
+        """Gets karma"""
+        return "Karma for {} is {}".format(args, self.karma[args])