Update pip package

[pavelloz]

It looks like there is an old version that doesnt have -d argument yet.

pawel-docs|performance⚡ ⇒ slack -d
usage: slack [-h] [-w WEBHOOK_URL] [-c CHANNEL] [-u USERNAME] [-i ICON_URL]
             [-e ICON_EMOJI] [-a] [-C COLOR] [-t TITLE]
             [text]
slack: error: unrecognized arguments: -d
pawel-docs|performance⚡ ⇒ slack --dump-json
usage: slack [-h] [-w WEBHOOK_URL] [-c CHANNEL] [-u USERNAME] [-i ICON_URL]
             [-e ICON_EMOJI] [-a] [-C COLOR] [-t TITLE]
             [text]
slack: error: unrecognized arguments: --dump-json