Plugins: Add plugin for saying no to 'sir'.

we have added a plugin and related test
to prevent any contributor from saying sir.

Closes #337

plugins/no_sir.plug

@@ -0,0 +1,11 @@
+[Core]
+name = no_sir
+module = no_sir
+
+[Documentation]
+description = Tell people to not use 'sir' when they do.
+
+[Python]
+version = 3
+
+[Errbot]

plugins/no_sir.py

@@ -0,0 +1,20 @@
+import re
+from errbot import BotPlugin
+
+
+class no_sir(BotPlugin):
+    """
+    Do not use sir
+    """
+
+    def callback_message(self, msg):
+        emots = [':D']
+        match_sir = re.search(r'\bsir\b', '\bSir\b', msg.body)
+        if match_sir:
+            self.send(
+              msg.frm,
+              '@{}, Do not use sir in your conversation. {}'.format(
+                  msg.frm.nick
+
+                )
+            )

tests/no_sir_test.py

@@ -0,0 +1,9 @@
+import plugins.no_sir
+
+
+class Test_no_sir(object):
+    extra_plugin_dir = '.'
+
+    def test_no_sir(self, testbot):
+        testbot.push_message(r'\bsir\b', '\bSir\b', msg.body)
+        assert 'Do not use sir in your conversation' in testbot.pop_message()