contrib_bots: Restructure bots to follow a consistent structure.

Now all the bots that are stored in contrib_bots are in the
same file/directory format.
The format is specified here #3427. Add tests.py file for encrypt_bot as well.
Fixes #3427.

contrib_bots/bots/encrypt_bot/tests.py

@@ -0,0 +1,33 @@
+import encrypt_bot
+
+def test():
+    for cmd, expected_response in sample_conversation():
+        message = {'content': cmd, 'subject': 'foo',
+                   'display_recipient': 'bar'}
+
+        class ClientDummy(object):
+            def __init__(self):
+                self.output = ''
+
+            def send_message(self, params):
+                self.output = params['content']
+        handler = encrypt_bot.EncryptHandler()
+        client_dummy = ClientDummy()
+        handler.handle_message(message, client_dummy, '')
+        if client_dummy.output != expected_response:
+            raise AssertionError('''
+                cmd: %s
+                expected: %s
+                but got : %s
+                ''' % (cmd, expected_response, client_dummy.output))
+
+def sample_conversation():
+    return [
+        ('@encrypt Please encrypt this', 'Encrypted/Decrypted text:  Cyrnfr rapelcg guvf'),
+        ('@encrypt Let\'s Do It', 'Encrypted/Decrypted text:  Yrg\'f Qb Vg'),
+        ('@encrypt ', 'Encrypted/Decrypted text:  '),
+        ('@encrypt me&mom together..!!', 'Encrypted/Decrypted text:  zr&zbz gbtrgure..!!'),
+    ]
+
+if __name__ == '__main__':
+    test()