Ability to unfollow entities

[plaurent]

Hi Dustin,

My first pull request. I've added code to CocoaTent which allows you to unfollow an entity. Because unfollowing in the tent.io API requires an id (rather than the entity name), this code first scans the followings to find the id for the entity name.

Best, Patryk / Pakl

- (void) unfollowEntity:(NSString *)entityName
{
    AFJSONRequestOperation *operation = [self.cocoaTentCommunication newJSONRequestOperationWithMethod:@"GET" pathWithoutLeadingSlash:@"followings" HTTPBody:nil sign:YES success:^(NSURLRequest *request, NSHTTPURLResponse *response, id JSON) {
        bool FOUND = NO;
        NSArray *entities = [JSON valueForKeyPath:@"entity"];
        NSArray *tent_ids = [JSON valueForKeyPath:@"id"];
        for (int i = 0; i < [entities count]; i++){
            NSString *entity = [entities objectAtIndex:i];
            NSString *tentid = [tent_ids objectAtIndex:i];
            if ([entity isEqualToString:entityName]) {
                FOUND = YES;
                [self unfollowTentID:tentid];
            }
        }
        if (FOUND) {
            NSLog(@"Found entity and id to unfollow, OK.");
        } else {
            NSLog(@"Did not find entity and id to unfollow.  Show NOT FOLLOWING message.");
        }
    } failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, id JSON) {
        [[NSNotificationCenter defaultCenter] postNotificationName:@"receiveDataFailure" object:nil];
        NSLog(@"failure, %@ \n\nwith request %@", error, [request allHTTPHeaderFields]);
    }];

    [operation start];
}

-(void) unfollowTentID:(NSString *)tent_id
{
    NSString *path = [NSString stringWithFormat:@"followings/%@", tent_id];

    AFJSONRequestOperation *operation = [self.cocoaTentCommunication newJSONRequestOperationWithMethod:@"DELETE" pathWithoutLeadingSlash:path HTTPBody:nil sign:YES success:^(NSURLRequest *request, NSHTTPURLResponse *response, id JSON) {

        NSLog(@"unfollow succeeded!");
    } failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, id JSON) {
        NSLog(@"unfollow failed");
    }];
    [operation start];
}

[dustinrue]

Thanks