Allow use of custom parameters on rtm_connect() (#210)

* Update client.py

* Update server.py

* Update client.py

* Update server.py

Author: kamushadenes

slackclient/client.py

@@ -2,6 +2,7 @@
 # mostly a proxy object to abstract how some of this works
 
 import json
+import traceback
 
 from .server import Server
 
@@ -33,7 +34,7 @@ def __init__(self, token, proxies=None):
     def append_user_agent(self, name, version):
         self.server.append_user_agent(name, version)
 
-    def rtm_connect(self, with_team_state=True):
+    def rtm_connect(self, with_team_state=True, **kwargs):
         '''
         Connects to the RTM Websocket
 
@@ -47,9 +48,10 @@ def rtm_connect(self, with_team_state=True):
         '''
 
         try:
-            self.server.rtm_connect(use_rtm_start=with_team_state)
+            self.server.rtm_connect(use_rtm_start=with_team_state, **kwargs)
             return True
         except:
+            traceback.print_exc()
             return False
 
     def api_call(self, method, timeout=None, **kwargs):

slackclient/server.py

@@ -66,10 +66,10 @@ def __repr__(self):
     def append_user_agent(self, name, version):
         self.api_requester.append_user_agent(name, version)
 
-    def rtm_connect(self, reconnect=False, timeout=None, use_rtm_start=True):
+    def rtm_connect(self, reconnect=False, timeout=None, use_rtm_start=True, **kwargs):
         # rtm.start returns user and channel info, rtm.connect does not.
         connect_method = "rtm.start" if use_rtm_start else "rtm.connect"
-        reply = self.api_requester.do(self.token, connect_method, timeout=timeout)
+        reply = self.api_requester.do(self.token, connect_method, timeout=timeout, post_data=kwargs)
 
         if reply.status_code != 200:
             raise SlackConnectionError