Adding feature to remove reactions (#101)

* Adding feature to remove reactions

Per enhancment request #100 this adds a method to the Message class
called remove_reaction() which takes in the emoji_name to be removed as
a parameter.

* Adding '/users/' to reaction delete url

mmpy_bot/dispatcher.py

@@ -294,6 +294,10 @@ def react(self, emoji_name):
         self._client.react_msg(
             self._body['data']['post']['id'], emoji_name)
 
+    def remove_reaction(self, emoji_name):
+        self._client.remove_reaction(
+            self._body['data']['post']['id'], emoji_name)
+
     def docs_reply(self, docs_format='    • `{0}` {1}'):
         reply = [docs_format.format(v.__name__, v.__doc__ or "")
                  for p, v in iteritems(self._plugins.commands['respond_to'])]

mmpy_bot/mattermost.py

@@ -37,6 +37,11 @@ def create_reaction(self, user_id, post_id, emoji_name):
                 'emoji_name': emoji_name,
             })
 
+    def delete_reaction(self, user_id, post_id, emoji_name):
+        return self.delete(
+            '/users/{0}/posts/{1}/reactions/{2}'.format(
+                user_id, post_id, emoji_name))
+
     def create_post(self, user_id, channel_id, message,
                     files=None, pid="", props=None):
         return self.post(
@@ -167,6 +172,13 @@ def post(self, request, data):
             verify=self.ssl_verify
         ).text)
 
+    def delete(self, request):
+        return json.loads(requests.delete(
+            self.url + request,
+            headers=self._get_headers(),
+            verify=self.ssl_verify
+        ).text)
+
     def put(self, request, data):
         return json.loads(requests.put(
             self.url + request,
@@ -229,6 +241,10 @@ def react_msg(self, post_id, emoji_name):
         return self.api.create_reaction(self.user["id"],
                                         post_id, emoji_name)
 
+    def remove_reaction(self, post_id, emoji_name):
+        return self.api.delete_reaction(self.user["id"],
+                                        post_id, emoji_name)
+
     def channel_msg(self, channel, message, files=None, pid="", props=None):
         c_id = self.channels.get(channel, {}).get("id") or channel
         return self.api.create_post(self.user["id"], c_id,