pronouns: add .clearpronouns command

Author: eliocamp

sopel/modules/pronouns.py

@@ -120,3 +120,12 @@ def set_pronouns(bot, trigger):
     bot.reply(
         "Thanks for telling me! I'll remember you use {}.{}".format(pronouns, disambig)
     )
+
+
+@plugin.command('clearpronouns')
+def unset_pronouns(bot, trigger):
+    """Clear pronouns for the given user."""
+    bot.db.delete_nick_value(trigger.nick, 'pronouns')
+    bot.reply(
+        "Okay. I'll forget your pronouns."
+    )