slackr 2.4.1

• Deprecates the bot_user_oauth_token argument for slackr* functions in favor of token
• Allows users to choose between a user token and a bot token
• Uses withr::local_options(list(cli.num_colors = 1)) inside of slackr to fix garbled tibble printing. linked issue
• Removes the channel, username and icon_emoji parameters for slackr_bot() which were deprecated in version 2.1.1 and have no effect
• Removes the cacheChannels parameter for slackr_setup() which was deprecated in version 2.1.0
• Removes hard-coded locale settings. linked issue
• Small error handling improvements and other miscellaneous fixes